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  • 1985-1989
  • 1975-1979  (551)
  • 1975  (551)
  • Cell & Developmental Biology  (476)
  • Ultrastructure  (75)
  • 1
    Electronic Resource
    Electronic Resource
    Torpide verlaufende Degeneration des äußeren Pallidumgliedes mit Bielschowsky-Körperchen (1975)
    Springer
    Journal of neurology 210 (1975), S. 191-198 
    Details
    ISSN: 1432-1459
    Keywords: Pallidumdegeneration ; Bielschowsky bodies ; Lafora bodies ; Corpora amylacea ; Ultrastructure ; Torsion dystonia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einem 60 Jahre alt gewordenen Mann, mit einer bis in die Kindheit zurückreichenden und extrem langsam progredienten, wahrscheinlich torsionsdystonischen bzw. choreoathetoiden Bewegungsstörung, fand sich eine isolierte Degeneration des äußeren Pallidumgliedes mit intraneuronaler Ablagerung von Bielschowsky-Körperchen und nur geringgradigem Nervenzellausfall. Die Bielschowsky-Körperchen zeigen den gleichen Aufbau wie Corpora amylacea und Lafora-Körperchen. Sie dürften ebenfalls Produkt einer cellulären, vorwiegend den Kohlenhydrat-stoffwechsel treffenden Dysmetabolie sein, die allerdings hier exquisit systembezogen auf die Neurone des äußeren Pallidumgliedes begrenzt ist und erst sehr spät bei fortgeschrittener Stapelung der Metabolite zum Untergang der Nervenzellen führt. Dieser Umstand erklärt den überaus torpiden Verlauf der Erkrankung.
    Notes: Summary In a 60-year-old man with a very slowly progressive motor disturbance probably of torsion dystonic or choreoathetotic type which started in childhood, we found an isolated degeneration of the exterior pallidum with intraneuronal deposition of Bielschowsky bodies and only slight deficit of neurons. The Bielschowsky bodies show the same structure as corpora amylacea and Lafora bodies. They might also be the result of a cellular disturbance mainly concerning the carbohydrate metabolism. In this case they are localised only in the neurons of the exterior part of the pallidum—in contrast to the organogenitically otherwise deriving (from the nuel. entopeduncularis) intact neurons of the pallidum internum—and they induce, after an excessive accumulation of the metabolites, not till extremely late loss of neurons. This circumstance explains the very torpid progress of this disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316246
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  • 2
    Electronic Resource
    Electronic Resource
    Niemann-Pick's disease (1975)
    Springer
    Journal of neurology 211 (1975), S. 61-68 
    Details
    ISSN: 1432-1459
    Keywords: Niemann-Pick ; Liver ; Sural nerve ; Ultrastructure ; Lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das klinische, biochemische und ultrastrukturelle Bild einer Sphingolipidose vom Typ Niemann-Pick wurde an Hand eines Patienten mit der infantilen Form (A) dargestellt. Die Diagnose wurde klinisch auf Grund einer rasch progredienten psychomotorischen Retardation mit Hepatosplenomegalie sowie typischen Schaumzellen im Knochenmark gestellt und durch den Nachweis von exzessiver Speicherung von Sphingomyelin in einer Leberbiopsie und das Fehlen der Sphingomyelinase bestätigt. Ultrastrukturell konnte eine Anhäufung von präsumptiven Phospholipiden in den Lysosomen von Leber und peripherem Nerv festgestellt werden. Obwohl weder eine axonale Degeneration noch eine Demyelinisierung im biopsierten Nerv gefunden werden konnte, war die Nervenleitgeschwindigkeit in den peripheren Nerven beim Patienten schon bei der Diagnosestellung deutlich herabgesetzt. Die Bedeutung der Befunde wurde diskutiert.
    Notes: Summary A diagnosis of Niemann-Pick disease type A was made in a 6-month-old boy on the grounds of progressive psychomotor retardation, hepatosplenomegaly, typical foam cells in the bone marrow and a deficiency of sphingomyelinase in a liver biopsy. Typical ultrastructural changes in lysosomes were found in hepatocytes and in Schwann cells. In spite of the absence of gross morphological changes in the axons and in the myelin sheath of the peripheral nerve biopsy, the nerve conduction velocity in the patient was greatly reduced. The ultrastructural aspect of the lysosomal inclusion suggested the storage of a phospholipid. Biochemical analysis of the liver biopsy demonstrated an increased content of total phospholipid of which sphingomyelin made up for more than 60%. The significance of these data are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312464
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  • 3
    Electronic Resource
    Electronic Resource
    Studies on the liver of Xenopus laevis (1975)
    Springer
    Anatomy and embryology 146 (1975), S. 265-277 
    Details
    ISSN: 1432-0568
    Keywords: Granulocytopoiesis ; Perihepatic layer ; Mesothelium ; Amphibia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Peritoneal-Überzug und die subkapsuläre Region der Leber von Xenopus laevis wurden mit dem Elektronenmikroskop untersucht. Dabei wurde festgestellt, daß in der subkapsulären Region eine zwei bis zehn Zellschichten starke perihepatische Schicht vorhanden ist. Die perihepatische Schicht setzt sich zum größten Teil aus granulocytopoetischem Gewebe zusammen. Es wurden jedoch auch Lymphocyten, Pigmentzellen und Fettspeicherzellen gefunden. Das Vorhandensein einer perihepatischen granulocytopoetischen Schicht bei Xenopus laevis steht im Gegensatz zu der bisherigen Auffassung, daß die perihepatische Schicht ein typisches Merkmal der Urodelen sei. Es werden die phylogenetische Bedeutung einer solchen Schicht bei Anuren sowie die Entwicklungsvorgänge der einzelnen Zelltypen der perihepatischen Schicht diskutiert. Außerdem wird auf die mögliche Bedeutung der perihepatischen Schicht für immun-Vorgänge verwiesen.
    Notes: Summary The peritoneal cover and the subcapsular region of the liver of Xenopus laevis were examined with electron microscopy. In the subcapsular region a prominent perihepatic layer two to ten cells wide was found. This perihepatic layer is mainly composed of granulocytopoietic tissue. Other cell types found in the perihepatic layer were lymphocytes, pigment cells and fat storing cells. The presence of a perihepatic granulocytopoietic layer in the liver of Xenopus laevis is in contrast to current opinion that such a layer is a characteristic typical of urodeles. The phylogenetic significance of such a layer in anurans and the developmental processes of the individual cell types of the perihepatic layer are discussed. Furthermore the possible participation of the perihepatic layer in the immune response is considered
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302174
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  • 4
    Electronic Resource
    Electronic Resource
    Fixation of foetal pig liver for electron microscopy (1975)
    Springer
    Anatomy and embryology 147 (1975), S. 243-258 
    Details
    ISSN: 1432-0568
    Keywords: Fixation ; Foetus ; Liver cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscopic investigations of the ability of various fixatives to preserve foetal pig liver tissue (immersion fixed 5 min, 20 min, and 40 min after the death of the mother) gave the following results: 1) Fixation with 4% formaldehyde gives, in all circumstances, an unacceptable tissue preservation. 2) Fixation with 2.5% glutaraldehyde gives fair tissue preservation in a ca. 130 μ thick zone below the surface. 3) Fixation with a fixative mixture containing 2% formaldehyde and 1.25% glutaraldehyde or 2% formaldehyde, 1% glutaraldehyde and 1% acrolein gives good tissue preservation in a ca. 500 μ thick zone under the surface. 4) The addition of DMSO does not improve tissue preservation. 5) Delayed fixation of liver tissue removed from the foetus after the uterus has been placed in an incubator for 40 min has only a slight effect on tissue preservation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315074
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  • 5
    Electronic Resource
    Electronic Resource
    Quantitative studies of the effect of progesterone on endometrial morphology of the spayed rat (1975)
    Springer
    Anatomy and embryology 148 (1975), S. 47-58 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Endometrium ; Ultrastructure ; Progesterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of various dosages and of various time periods of treatment with progesterone have been studied in the spayed, mature rat. Test objects were the cells of the luminal epithelium and of the endometrial stroma which were examined by qualitative and quantitative electron microscopy. No significant response was observed in epithelial or stromal cells until after 12 hrs of progesterone treatment. The nuclei of both cell types were then more circular than earlier with reduced long diameters. The functional significance of this change in configuration is unclear since only in the stromal cells was it followed by nuclear growth. Further, after 12 hrs of treatment the relative amounts of mitochondria and granular endoplasmic reticulum of stromal cells were reduced while the volume of the stromal cell cytoplasm appeared enlarged. This is taken as evidence that progesterone causes an intracellular oedema probably by decreasing cell membrane permeability. This response is probably not specific for the stroma but also includes the luminal epithelium, although the volume of the epithelial cell cytoplasm could not be determined here. Nucleolar enlargement did occur in stromal cells and was observed after 12 hrs of treatment but was not significant until after 24 hrs. At this point of time the net amount of granular endoplasmic reticulum in stromal and epithelial cells was increased indicating an increased protein synthesis in both cell types. However, only in the stromal cells was this associated with nucleolar enlargement, which supports the idea that progesterone stimulates protein synthesis through different mechanisms in the two cell types. Testing various dosages of progesterone showed that 0.5 mg had an effect similar to 5 mg of progesterone. When 0.05 mg progesterone was injected the only effect observed was an increase in the amount of apical vesicles of the luminal epithelium, showing that the epithelium is more sensitive to progesterone than the stroma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315562
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  • 6
    Electronic Resource
    Electronic Resource
    Studies on the liver of Xenopus laevis (1975)
    Springer
    Anatomy and embryology 146 (1975), S. 245-264 
    Details
    ISSN: 1432-0568
    Keywords: Hepatocytes ; Amphibia ; Glycogen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Leber von Xenopus laevis wurde mit dem Elektronenmikroskop untersucht. Dabei wurde festgestellt, daß sie in ihrem Bau stark von der Leber der Säuger abweicht, vor allem in Bezug auf die Morphologie des als typisch zu bezeichnenden Hepatocyten. Die Untersuchungen zeigten, daß eine solche Zelle primär Glykogenspeicherungs-Funktion besitzt und nur geringe Bestandteile an Organellen und anderen Inklusionen aufweist. Da dieser Zelltyp in der Leber unbehandelter Tiere am häufigsten auftritt, wurde er als Normalzelle bezeichnet. Bemerkenswert erschien die Tatsache, daß eine Vielzahl von Zelltypen in der Normalleber vorkommen, die sonst vermehrt unter experimentellen Bedingungen zu finden sind, z.B. Zellen mit stark vermehrtem RER, vergrößertem Golgi-Feld, vermehrten Lipidinklusionen etc. Diese hohe Zahl von abweichenden Hepatocyten und die Tatsache, daß alle Zwischenstufen zwischen den einzelnen Extremen vorhanden sind, die nicht durch die lage der Zelle innerhalb der Leber erklärt werden konnten, wurden als der Ausdruck eines zyklischen Durchlaufens der einzelnen Aktivitätsstadien interpretiert. Spezielles Interesse verdient die Tatsache, daß Glykogen in der Leberzelle vermehrt nur während der Vitellogenese abgebaut wird. Akuter und chronischer Hunger, sowie Kälte-adaptation beeinflussen die Morphologie der Normalzelle, besonders in Bezug auf das Glykogen kaum. Die möglichen Ursachen hierfür werden diskutiert.
    Notes: Summary The liver of Xenopus laevis was examined with electron microscopy. Its structure was found to be markedly different from that of mammals, particularly regarding the morphology of the hepatocytes to be classified as typical. It was established that the main function of such a cell is the storage of glycogen, and further that it possesses only scant organelles and other inclusions. Since this type of cell was found most frequently in the liver of untreated animals, it was designated as normal cell. The fact appears noteworthy that in the normal liver of Xenopus laevis an abundance of cell types occur which are otherwise found to be proliferated under experimental conditions, e.g. cells with pronouncedly augmented RER, enlarged Golgi complexes, increased lipid inclusions etc. This high number of divergent hepatocytes and the fact that all intermediate stages between the individual extremes are present and not to be accounted for by the position of the cell within the liver was interpreted as being the expression of a cyclic passage of the various stages of activity. It is of special interest that augmented degradation of glycogen in the liver cell takes place only during vitellogenesis. Acute and chronic hunger, as well as adaptation to cold, hardly affect the morphology of the normal cell, especially as far as the glycogen is concerned. The possible causes for this are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302173
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  • 7
    Electronic Resource
    Electronic Resource
    Fine structure of the interrenal cell in the quail and the pigeon (1975)
    Springer
    Anatomy and embryology 146 (1975), S. 301-311 
    Details
    ISSN: 1432-0568
    Keywords: Endocrinology ; Ultrastructure ; Adrenal cortex ; Avian Physiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural characteristics of the interrenal cell were investigated in the quail and the pigeon after fixation by intravascular addominal perfusion. These is no significant fine structural difference between cells belonging to subcapsular and central regions of the gland. The interrenal cell in both species possesses nuclear bodies, polymorphic mitochondria with tubulo-vesicular cristae and tubular crystalline inclusions, considerable amounts of endoplasmic reticulum, ergastoplasm, a well developed Golgi apparatus, coated vesicles, microtubules, filaments, cilia, ribosomes, a profusion of liposomes, dense bodies with varied inner structure, pinocytic invaginations of cell membrane and intercellular attachment devices. The pigoen adrenocortical cell also possesses intranuclear lipidlike inclusions and fibrous bundle (this being never recorded in adrenocortical cell), annulate lamellae, and a variety of cytosomes, probably lipofucsin in nature. The significance and cytophysiological role of various organelles and inclusions have been discussed in the light of earlier data obtained on avian adrenocortical cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302176
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  • 8
    Electronic Resource
    Electronic Resource
    Intranuclear inclusions in a case of Creutzfeldt-Jakob disease (1975)
    Springer
    Acta neuropathologica 31 (1975), S. 353-361 
    Details
    ISSN: 1432-0533
    Keywords: Intranuclear Inclusions ; Creutzfeldt-Jakob Disease ; Ultrastructure ; Virus-Like Inclusions ; Nuclear Body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two types of intranuclear inclusions were described in a brain biopsy from a patient with Creutzfeldt-Jakob disease. The first type of intranuclear inclusion was papova virus-like and was observed within 20% of the nuclei of all astrocytes and neurons examined. The particles measured 32 nm in diameter and consisted of a dense core surrounded by a multilayered shell. The second type of intranuclear inclusion was a granulo-fibrillar nuclear body found within the nuclei of astrocytes and neurons. The possible significance of these inclusions to the etiology of Creutzfeldt-Jakob disease is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687930
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  • 9
    Electronic Resource
    Electronic Resource
    Tissue culture study of a sacrococcygeal chordoma with further ultrastructural study (1975)
    Springer
    Acta neuropathologica 32 (1975), S. 225-233 
    Details
    ISSN: 1432-0533
    Keywords: Tissue Culture ; Ultrastructure ; Chordoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an electron microscopic study of a sacrococcygeal chordoma and its in vitro cultured cells. In vitro, the cells that proliferated in the early phase were predominantly non-vacuolated stellate cells, which were later transformed into vacuolated cells. This suggests that various cell types seen in vivo represent variants of the same cell type at different stages of differentiation and cellular activity. The in vitro tumor cells also show the origin of their vacuoles from both rough endoplasmic reticulum and Golgi membranes. The finding of amorphous and granular material and collagen fibrils in the extracellular spaces of cultured cells seems to suggest that chordoma cells have certain synthetic and secretory activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696571
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  • 10
    Electronic Resource
    Electronic Resource
    Fabry's disease on the mechanism of the peripheral nerve involvement (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 9-21 
    Details
    ISSN: 1432-0533
    Keywords: Fabry's Disease ; Glycolipid ; Anhydrosis ; Pain ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A sural nerve biopsy of a patient with Fabry's disease showed depletion of larger myelinated fibres, but smaller myelinated and unmyelinated fibres were intact. Epineurial and to a lesser degree endoneurial vessels revealed abundant lamellar inclusions in the endothelial and perithelial cells. Larger myelinated nerve fibres contained glycogen granules in the vacuoles caused by splitting of the adaxonal membranes. A skin biopsy revealed abundant inclusions in the secretory cells and myoepithelial cells of the sweat glands. The lumen of the gland was packed with inclusions like those in the vessel walls. The pain and anhydrosis might be caused by accumulation of glycolipid in the vasa nervorum and sweat glands and not by autonomic nerve involvement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685960
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  • 11
    Electronic Resource
    Electronic Resource
    Intracranial hemangiopericytoma (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 279-284 
    Details
    ISSN: 1432-0533
    Keywords: Hemangiopericytoma ; Leiomyoblastic differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two intracranial hemangiopericytomas revealed subcellular features of the neoplastic elements comparable to those observed in normal and neoplastic smooth muscle. These included intracytoplasmic and submembranous fusiform dense bodies associated with bundles of filaments, tapered configuration of cells with grouping of cytoplasmic organelles at nuclear poles and deposition of intercellular basal lamina-like material. These observations are consistent with the pericytic origin but opposed to the ofttimes postulated meningothelial derivation of the neoplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686160
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  • 12
    Electronic Resource
    Electronic Resource
    The occurrence of dark neurons in the normal and deafferentated lateral vestibular nucleus in the rat (1975)
    Springer
    Acta neuropathologica 31 (1975), S. 117-127 
    Details
    ISSN: 1432-0533
    Keywords: Dark Neurons ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lateral vestibular nucleus was studied by light and electron microscopy in normal rats as well as in rats in which the anterior cerebellar vermis was destroyed. Dark neurons were seen in many of the operated rats but were rarely found in normal control animals. The dark neurons were not seen in adjacent nuclei. In additional rats, it was found that anoxia, extra anaesthetic, postmortem rough handling, and sham operations did not increase the frequency of dark neurons. These data indicate that dark neurons might not always be artifactual and that the lateral vestibular nucleus appears to be a focal point for their occurrence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688146
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  • 13
    Electronic Resource
    Electronic Resource
    Ultrastructural changes of the endocrine pancreas in pregnant rats (1975)
    Springer
    Diabetologia 11 (1975), S. 285-289 
    Details
    ISSN: 1432-0428
    Keywords: Ultrastructure ; pregnancy ; B-cell ; granule type ; light (pale) granules ; dark granules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultramicroscopic appearence of the B-cell of the pregnant rat suggests hyperinsulinism of the individual beta cell. In pregnant rats the B-cell contains an increased volume and an increased number of light granules as well as enlarged mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00422393
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  • 14
    Electronic Resource
    Electronic Resource
    La paroi cellulaire de Coelastrum (Chlorophycées) (1975)
    Springer
    Archives of microbiology 102 (1975), S. 95-101 
    Details
    ISSN: 1432-072X
    Keywords: Coelastrum ; Chlorococcales ; Chlorophyta ; Ultrastructure ; Cell Wall ; Tubules ; Bristles ; Polymorphism ; Buoancy ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La paroi cellulaire de Coelastrum est généralement composée de trois couches. La couche la plus externe a été plus particulièrement étudiée. Elle est composée de tubules dressées, et porte souvent de longues fibrilles dont le rôle serait de stabiliser l'algue dans son milieu. La morphologie de la paroi cellulaire peut se modifier en fonction du milieu.
    Notes: Abstract The cell wall of Coelastrum is usually composed of three layers. The outermost layer was studied most extensively. It consists of erect tubules which often bear long bristles whose function may be to stabilize the algae in its environment. The cell wall can modify its morphology according to the environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428352
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  • 15
    Electronic Resource
    Electronic Resource
    Ultrastructural changes occurring during germination and outgrowth of spores of the thermophile Bacillus acidocaldarius (1975)
    Springer
    Archives of microbiology 102 (1975), S. 155-161 
    Details
    ISSN: 1432-072X
    Keywords: Bacillus acidocaldarius ; Spores ; Germination ; Thermophile ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Spores of the thermophilic, acidophilic, Bacillus acidocaldarius were covered by a thick outer coat and a laminated inner coat (5.5 nm periodicity). Small membranous vesicles were present in the spore core and they disappeared as germination proceeded. After depolymerization of the cortex, and a 30% increase in spore diameter, a localized gap appeared in the laminated inner coat only. This inner coat gap was narrow and could be the whole length of the spore. The germ cell appeared to grow, or to be pushed towards the inner coat gap, at which stage the outer coat disappeared in the same localized area. As the vegetative cell grew out the spore coat fell away, with loose cortical material still attached to it. The young germ cell developed a large spherical electron dense inclusion body in the cytoplasm, at the same time as the ribosomal and nuclear areas became distinct.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428361
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  • 16
    Electronic Resource
    Electronic Resource
    Cell wall enzymatic lysis of the yeast form of Pullularia pullulans and wall regeneration by protoplasts (1975)
    Springer
    Archives of microbiology 104 (1975), S. 271-277 
    Details
    ISSN: 1432-072X
    Keywords: Protoplasts ; Regeneration ; Wall Structure ; Pullularia ; Ultrastructure ; Membrane Splitting ; Aberrant Tubes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the process of degradation of the cell wall of the yeast form of Pullularia pullulans by the lytic system of Micromonospora chalcea samples were withdrawn at different times and observed under phase contrast and electron microscope. The progressive lysis of the walls reveals a fibrillar component inside the apparently amorphous wall. Freeze etched preparations of cells during the formation and regeneration of protoplasts show that the cellular membrane is split and this method allows the smooth external face of the membrane and other internal face covered by particles to be seen. The fact that the smooth face of the membrane is only visible during the preparation or the regeneration of protoplasts and very rarely when intact cells are fractured, suggests a strong adherence between cell wall and this external layer of the membrane. During the regeneration which takes place as in most of the yeasts and moulds, a special study of the extension of the cell wall is made and a possible mechanism for this extension of the regenerated cell wall is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00447336
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  • 17
    Electronic Resource
    Electronic Resource
    Effects of diazepam on photosynthesis, respiration, rubidium uptake, and finestructure of Scenedesmus obliquus in synchronous cultures (1975)
    Springer
    Archives of microbiology 102 (1975), S. 129-137 
    Details
    ISSN: 1432-072X
    Keywords: Diazepam ; Benzodiazepines ; Scenedesmus ; Ultrastructure ; Photosynthesis ; Respiration ; Rubidium Uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Effects of diazepam (Valium) on photosynthesis, chlorophyll/photosynthesis ratios, respiration, uptake of rubidium ions, and ultrastructure of Scenedesmus obliquus synchronized by a light-dark regimen of $$14:\overline {10}$$ hrs were determined. 80 and 160 μM diazepam, added to the nutrient medium at the start of the light-dark change (i.e., start of the cell cycle) gradually reduced rates of photosynthesis below the initial rates from the beginning of the experiment. Contents of chlorophyll, however, remained nearly unaffected. Consequently, the diazepam-treated cells had a higher chlorophyll/photosynthesis ratio—also with regard to respiration in order to calculate the gross photosynthesis. The occurrence of photorespiration cannot be assumed. The net influx or rubidium was slightly reduced by 100 μM diazepam 0.5 and 2.0 hrs after the start of the cell cycle and was strongly inhibited after 5 to 14 hrs. 80 and 160 μM diazepam caused separation of thylakoids, formation of giant mitochondria and enlargement of vacuoles. The results are discussed and it is finally suggested that diazepam acts on different membrane systems. Furthermore an ATP deficiency cannot be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00428357
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  • 18
    Electronic Resource
    Electronic Resource
    The direct spinal area of the inferior olivary nucleus: An electron microscopic study (1975)
    Springer
    Experimental brain research 22 (1975), S. 13-24 
    Details
    ISSN: 1432-1106
    Keywords: Inferior olive ; Spinal afferents ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Identification of the direct spinal areas (portions of the dorsal and medial accessory nuclei) within the opossum inferior olivary complex was accomplished by mapping the location of the terminal degeneration by the Fink-Heimer technique subsequent to cervical cord lesions. Following similar lesions, sampling of these same regions for electron microscopic study was assured by examination of transversely oriented, 1 μ plastic sections prior to thin sectioning. The first evidence of electron dense axon terminals was found at a survival time of 24 hours. At survival times of 36, 48 and 72 hours, degenerating presynaptic profiles shrink, become irregular in shape and are totally or partially surrounded by glial processes. Spinal terminals average 1–2 μ in their greatest dimension, contain round, clear synaptic vesicles and generally contact small diameter (0.4–1.8 μ) dendritic shafts or occasional spiny appendages. The spiny dendritic appendages make up the central core of the olivary glomeruli and these juxtaposed dendritic processes exhibit gap junctions. At longer survival times (5, 7 and 9 days) many presynaptic profiles with either round or pleomorphic synaptic vesicles remain normal in appearance and contact dendritic shafts or the spiny appendages within glomeruli. Afferents from other sources (possibly including intrinsic neurons) must terminate within the direct spinal portion of the nuclear complex to account for the numerous axon terminals which retain normal morphology after such long survival times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235408
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  • 19
    Electronic Resource
    Electronic Resource
    Dissociated cell cultures from fetal mouse hypothalamus patterns of organization and ultrastructural features (1975)
    Springer
    Experimental brain research 23 (1975), S. 29-47 
    Details
    ISSN: 1432-1106
    Keywords: Cell cultures ; Fetal ; Hypothalamus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dissociated fetal hypothalamic cells mainly taken from 14 day-old mouse fetuses were grown in vitro for increasing time (9 to 60 days). Soon after inoculation the cells partly reaggregated and attached. The small reaggregates were then interconnected by fibers bundles. After the first week the cultures were composed of a continuous basal monolayer of flat and transparent cells, over which various types of refractile cells were lying in discontinuous areas. The ultra-structural study enabled us to identify these cell types, to describe their spatial relationships, and to follow their evolution with time in culture. The basal cell formed several superimposed layers. With increasing age, they displayed typical features of astrocytes and of ependymal cells. The latter exhibited rhythmic ciliary movements in culture. The overlying cells corresponded to three types which were associated in small clumps: primitive neuro-epithelial cells, maturing as well as mature neurons and typical neurosecretory cells. The latter cells were found as early as 9 days of culture of 14 day-old fetal hypothalamic cells and retained their typical features up to two months. Neuronal processes formed very dense networks at the surface of the cultures and terminated within the basal layers. Axon and dendrites were precociously found and were still present after two months. Within axon terminals dense-core vesicles appeared at the same time as neurosecretory cells. Synaptic vesicles and synaptic junctions were found later on.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238727
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  • 20
    Electronic Resource
    Electronic Resource
    The ultrastructure and development of the colonial sheath of Microcystis marginata (1975)
    Springer
    Archives of microbiology 106 (1975), S. 209-214 
    Details
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Colonial sheath ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The colonial sheath of Microcystis marginata has a definite structure as seen by light and electron microscopy, consisting of a relatively smooth inner surface and densely packed, long fibrils on the outer surface. The sheath initially forms around the single cell and expands by continual deposition of sheath material to accomodate the synchronously dividing cells of the colony.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446525
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  • 21
    Electronic Resource
    Electronic Resource
    Ultrastructural aspects of muscle and nerve in Werdnig-Hoffmann disease (1975)
    Springer
    Acta neuropathologica 31 (1975), S. 281-296 
    Details
    ISSN: 1432-0533
    Keywords: Werdnig-Hoffmann Disease ; Ultrastructure ; Denervation ; Muscle ; Myofibrils ; Centrioles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors describe in biopsies from 6 cases of Werdnig-Hoffmann disease, including 2 of the more benign type, the ultrastructural typical aspects of denervation. They compare their findings with those of other workers. The striking points are the great variation in the diameter of the muscle fibres and the myofibrils, the disorganisation of the myofibrils, the sarcomeres and the filaments, with persistance of the relations between thick and thin filaments at various levels, the modifications of the Z-band and the triads in chains. The folds and the basement membrane are examined. Centrioles are present in a muscle fibre and in a satellite. Glycogen is very abundant. The nerves seem normal but some Schwann cells contain π granules which are not observed usually at the age of the patient. The end plates and a muscle spindle are normal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687923
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  • 22
    Electronic Resource
    Electronic Resource
    An adult case of metachromatic leukodystrophy (1975)
    Springer
    Acta neuropathologica 32 (1975), S. 333-339 
    Details
    ISSN: 1432-0533
    Keywords: Adult Metachromatic Leukodystrophy ; Polarization Microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The findings are described in an adult case of metachromatic leukodystrophy examined by light, polarization and electron microscopy. Symmetrical demyelination was found in the cerebral hemispheres, but was moderate in the cerebellum, brain stem and spinal cord. Early changes in myelin of peripheral nerves have been demonstrated by polarization microscopy. Various metachromatic structures have been described in glial cells and neurons by electron microscopy, indicating disturbances at different metabolic steps of lipid metabolism. There are minor but no essential ultrastructural differences in the disease of different ages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696795
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  • 23
    Electronic Resource
    Electronic Resource
    Malignant fibrous mesothelioma (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 173-177 
    Details
    ISSN: 1432-0533
    Keywords: Mesothelioma ; Pleura ; Metastases ; Brain ; Ultrastructure ; Asbestos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A malignant fibrous mesothelioma in a 52 year old white man arising from the left parietal pleura associated with lupus erythematosus with metastases to brain and liver is reported. Asbestos bodies were found in digested pulmonary tissue but none in the primary or metastatic lesions. Light microscopic and ultrastructural studies suggest that this tumor contains mesothelial or endothelial cells, some of which revealed fibroblastic features while others disclosed epitheloid characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687543
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  • 24
    Electronic Resource
    Electronic Resource
    Wernicke's encephalopathy (1975)
    Springer
    Acta neuropathologica 31 (1975), S. 137-150 
    Details
    ISSN: 1432-0533
    Keywords: Thiamine Deficiency ; Wernicke's Encephalopathy ; Rhesus Monkey ; Ultrastructure ; Myelin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental Wernicke's encephalopathy, induced in rhesus monkeys with a diet lacking thiamine (vitamin B1), is characterized by cavitary necrosis of the striatum as well as a microvacuolar periventricular lesion of the brain stem such as occurs in man. With high resolution light microscopy and electron microscopy, the primary structural alteration in the brain stem lesion, and probably also in the striatum, appears to be that of widespread “blister” formation due to splitting of myelin at the intraperiod line. Microvascular alterations were minimal, even in the most severely affected regions. It is the myelin blisters which give rise to the spongy texture of the neuropil. A similar splitting of myelin has been deseribed in several other experimental encephalopathies, and it is probable that it also occurs in Wernicke's encephalopathy in man.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688148
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  • 25
    Electronic Resource
    Electronic Resource
    The onset and progress of transformation of avian slow into fast muscles under neural influence (1975)
    Springer
    Pflügers Archiv 360 (1975), S. 121-134 
    Details
    ISSN: 1432-2013
    Keywords: Muscle cross ; Myosin ATPase ; Ultrastructure ; Fibre types ; Light chains of myosin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The slow anterior latissimus dorsi (ALD) muscles of newly hatched chiekens were transposed and cross-innervated by the mixed, predominantly fast superior brachialis nerve, and investigated 2 to 15 months after the operation. Two months after the operation, myosin ATPase activity of the cross-innervated ALD muscles was still as low as in the control ALD, although the ultrastructure and the histochemical ATPase activity already showed a mixed fibre-type pattern with a predominance of fast-type fibres around the site of nerve implantation. The change of myosin properties of the whole cross-innervated ALD did not occur until the third month after the operation. At that time, the myosin ATPase activity increased about 2.5 times and light chains of myosin of the fast type appeared in the electrophoretic pattern. The myosin ATPase activity attained 62% of the activity found in the control fast posterior latissimus dorsi muscles at three months; subsequently it remained at about this level reaching 68% 18 months after the operation. The results indicate that approximately two thirds of the corss-innervated ALD muscle fibres became changed towards the fast type under neural influence, whereas about one third remained slow, being re-innervated by the slow-type motor fibres of the implanted nerve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00580535
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  • 26
    Electronic Resource
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    Ultrastructural studies on the myocardial capillaries of the experimentally lathyritic rat, protective effect of certain flavonoids (1975)
    Springer
    Virchows Archiv 365 (1975), S. 201-212 
    Details
    ISSN: 1432-2307
    Keywords: Lathyrism ; Capillaries ; Rat ; Ultrastructure ; Flavonoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of rat myocardial capillaries was studied in the course of experimental lathyrism. Endothelial cells were hypertrophic, with a sinuous profile of the plasma membrane facing the lumen and with a consistent increase of pinocytotic vesicles; the nuclei were irregular in shape; ATPase activity was no more demonstrable. Therefore, various and well distinct structural endothelial mechanisms seem to be primarily involved, causing an alteration of the dynamics of transcellular exchanges and of the permeability of the vascular wall. Simultaneous treatment with certain flavonoids, (O-(β-hydroxyethyl)-rutosides and Na(+)-epicatechin-2-sulfonate), resulted in a less pronounced alteration and a more rapid recovery. The possibility of the existence of a common site of action of lathyrogens and flavonoids is raised in the discussion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00434039
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  • 27
    Electronic Resource
    Electronic Resource
    Fenestrated blood capillaries and lymphatic capillaries in rat skeletal muscle (1975)
    Springer
    Cell & tissue research 163 (1975), S. 169-174 
    Details
    ISSN: 1432-0878
    Keywords: Muscles ; Blood supply ; Capillaries ; Lymphatic system ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Capillary fenestrae occur in one of about 60 cross-sectioned blood capillaries in normal adult rat skeletal muscles. The fenestrae occur singly or in groups. Fenestrated capillaries are found close to muscle fibers as well as in the perimysial and perineurial connective tissue. Small numbers of lymphatic capillaries are also present, mostly in the perimysial connective tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221724
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  • 28
    Electronic Resource
    Electronic Resource
    Hypertrophy of intestinal smooth muscle (1975)
    Springer
    Cell & tissue research 163 (1975), S. 199-214 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Intestine ; Hypertrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Proximal to an experimental stenosis of the small intestine of rats and guinea-pigs a remarkable hypertrophy of the muscle coat develops 3–5 weeks after the operation. There is no increase in the length of the intestine but an overall increase in volume of the muscularis externa up to 10 times. This increase is accounted for by an increase in size and in number (by mitosis) of smooth muscle cells of both the longitudinal and circular layers. Bundles of newly-formed smooth cells appear in the serosa and are circularly arranged. In the hypertrophic smooth muscle cells of the circular layer the ratio of surface to volume is 0.80 (0.80 μm2 of cell surface for every μm3 of cell volume) as against 1.4 in the control muscle. The hypertrophic muscle cells have a highly developed sarcoplasmic reticulum and show a large number of nexuses. The density of innervation (number of axons per given number of smooth muscle cells) is smaller than in controls. Few collagen fibrils are visible in the extracellular space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221727
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  • 29
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    Electronic Resource
    Chicken gonadotrophins: Their effects on the testes of immature and hypophysectomized Japanese quail (1975)
    Springer
    Cell & tissue research 156 (1975), S. 499-520 
    Details
    ISSN: 1432-0878
    Keywords: Gonadotrophins ; Testis ; Hypophysectomy ; Ultrastructure ; Japanese quail (Coturnix coturnix japonica)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Five-week old Japanese quail held under short daylengths (8L/16D) were injected daily for two weeks with 20 μg/day of purified chicken luteinizing hormone (LH) or with one of two chicken follicle-stimulating hormone (FSH) fractions. Both intact and hypophysectomized birds were used. After killing, the testes were weighed and fixed for light- and electron-microscopy. Following hypophysectomy testicular weights fell significantly below those of saline-injected controls, indicating that short day conditions are not equivalent to “physiological hypophysectomy”, the pituitary-gonadal axis continuing to function at a low level. Chicken LH stimulated differentiation of the interstitium, producing mature Leydig cells containing the full complement of organelles typical of steroid-secretion. In addition it induced some testicular growth caused by spermatogonial division and partial differentiation of the Sertoli cells. This effect was assumed to be a secondary response to androgen secretion but a direct action of chicken LH on the tubules is not dismissed. LH given to intact quail caused greater testicular growth, presumably due to synergism with endogenous hormones. Both chicken FSH fractions induced testicular growth and development; in intact birds the effects were similar to those observed in intact LH-treated birds. In hypophysectomized quail given FSH the testicular weights were greater than in hypophysectomized LH-treated birds and the seminiferous tubules were larger. Sertoli cells were stimulated and pachytene spermatocytes were numerous. Leydig cell differentiation was minimal in all FSH-treated birds, being less pronounced in hypophysectomized than in intact birds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225109
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  • 30
    Electronic Resource
    Electronic Resource
    The interstitial origin of germinal cells in the testis of the sticklebackThis investigation was supported by research grant AO657 from the National Research Council of Canada to D. B. McMillan. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 295-317 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The brook stickleback, Culaea inconstans (Kirtland), in common with other bony fishes, lacks a germinal epithelium in the tubules of the testis, and the tubule wall is composed of a thin, discontinuous layer of myoid cells and collagenous fibers. Labelling of germ cells with tritiated thymidine has shown that the germ cells are derived from clumps of spermatogonia in the interstitial area. Large companion cells within the lumina of the tubules extend their processes to engulf spermatogonia from the interstitium which then enter the lumen of the tubule. Subsequent development of the germ cells takes place within individual compartments formed by folds of the plasma membrane of a companion cell. The companion cell, together with its complement of germ cells, constitutes a cyst. A companion cell may surround spermatogonia in the interstitium and at the same time encompass residual sperm of the previous season within the lumen. The plasma membranes of the germ cells and the companion cells remain discrete. Mature sperm are released into the lumen of the tubule and the companion cell again extends its processes into the interstitium and engulfs more spermatogonia for the following year.Companion cells may be homologous to the Sertoli cells of higher vertebrates although their processes penetrate the interstitium during the initial stages of spermatogenesis and they do not contain a permanent stock of spermatogonia.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051450304
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    The cardiac muscle in the pulmonary vein of the rat: A morphological and electrophysiological studyWork done in the Department of Morphology of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, and Institute of Biophysics of the Federal University of Rio de Janeiro. Supported in part by the Fundação de Amparo à Pesquisa do Estado de São Paulo, grant 71/490 - médicas; by the Conselho de Pesquisas da Universidade Federal do Rio de Janeiro, by the Conselho Nacional de Pesquisas (Brasil), and by Banco Nacional de Desenvolvimento Econǒmico (Brasil) Contrato FUNTEC 143. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 409-433 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The pulmonary veins of albino Wistar rats were studied by means of light and electron microscopy. The media of larger veins consists of cardiac muscle fibers which extend until the vessels attain about 100 μ in diameter. This coat consists of external longitudinal fibers and internal circular fibers. The vasa vasorum are well developed and the capillaries show pseudofenestrations. The numerous adrenergic and cholinergic nerve endings do not form typical motor end-plates as seen in skeletal muscles. The ultrastructure of these media muscle fibers is similar to that of rat hearts. The smooth muscle layer of larger pulmonary veins is not continuous as it is in smaller veins where it forms cushions. Comparisons of albino rats and other rodents reveal striking differences.Action potential shape and propagation velocity (0.5-1.2 m/s) along the myocardial coat of the pulmonary vein were similar to those observed in the left atrium and so was their sensitivity to locally applied acetylcholine. The physiological direction of propagation in rat pulmonary veins is toward the lung. This finding lends support to the hypothesis of a rhythmic, valve-like action of the striated musculature of the pulmonary venous wall during the systole and a possible role in the capacitance of the pulmonary circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051450403
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  • 32
    Electronic Resource
    Electronic Resource
    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460101
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  • 33
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    Electronic Resource
    Cytological examination of reduction bodies of Corvomeyenia carolinensis harrison (Porifera: Spongillidae) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 483-491 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Freshwater sponges, Corvomeyenia carolinensis Harrison, were placed into tap water to induce degenerative reduction body formation. Reduction bodies were examined using light and electron microscopy in order to define their histochemical and ultrastructural characteristics. The reduction body of freshwater sponges is an extremely simple developmental system consisting primarily of an archeocyte reserve delimited by a simple squamous pinacoderm. The freshwater sponge reduction body displays many similarities to overwintering phases of marine sponges. The system presents an unusually straightforward vehicle for investigations of degeneration and regeneration as processes in developmental biology and may represent a reasonable vehicle in which to examine the process of the genesis of lysosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051450406
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    The aquiferous systems of three marine demospongiaePortions of this study were submitted for partial fulfillment of the M.A. degree in Zoology, University of California, Berkeley, California. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 493-502 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The aquiferous systems of three common, coastal, marine Demospongiae, Halichondria panicea (Pallas), Haliclona permollis (Bowerbank) and Microciona Prolifera (Ellis and Solander), are analyzed by measurements of cross-sectional areas of conducting elements. The patterns in demosponges of extremely different organizational morphologies are found to be quantitatively similar. The porocyte nature of the ostia is established for all three species. Choanocyte chamber densities range from 1 to 1.8 × 107 chambers ml-1 with 57 to 95 choanocytes per chamber (means). Cross-sectional area of the intervillar space of the choanocyte collars is calculated to be 12 to 56 times the lateral surface area of the specimen. Velocities of water movement through specific elements of the aquiferous system are calculated from cross-sectional area data and measured oscular flow of Haliclona permollis. The calculated Reynolds numbers lie below the critical value and fluid flow is thus considered laminar throughout the aquiferous systems of these sponges.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051450407
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  • 35
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    Electronic Resource
    Cytophysiological basis of disruptive pigmentary patterns in the leopard frog Rana pipiens. II. Wild type and mutant cell-specific patternsContribution Number 58 from the Amphibian Facility of the University of Michigan.,Supported in part by NSF GB 8187 to Dr. George W. Nace, University of Michigan. Data taken in part from a dissertation submitted to the University of Michigan in partial fulfillment of the requirements for the Ph.D. Manuscript preparation aided by grants from the Swarthmore College Faculty Research Fund, and NSF Institutional grant GU 3287 to George Washington University. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 35-54 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new pattern index, Ip, is introduced and used to compare patterns of wild type, burnsi, and kandiyohi chromatophores in the leopard frog, Rana pipiens. Wild type chromatophores are hyperdispersed over distances within cellular contact, and it is concluded that this hyperdispersion results from contact-mediated negative interactions. The hyperdispersion is less strong in spot cells than interspot, and extends over larger areas in burnsi than in wild type epidermis. Over areas greater than chromatophore size, patterns are either random or clumped. Patterning of kandiyohi melanophores is clumped into aggregates small enough to be within the range of cellular contact, suggesting a lack of contact inhibition among these cells. The possible roles of cellular properties and the extracellular environment in pattern determination are discussed.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460103
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    Evidence for diaphragms in the pores of annulate lamellae and the nuclear membraneThis investigation was supported by a grant from the National Science Foundation GB 2374, and in part by funds from the Harris McLaughlin Foundation. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 81-95 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Interpretation of cross and tangential sections of the annulate lamellae and nuclear membrane of Rana pipiens oocytes provides evidence in these structures for the existence of diaphragms spanning the pores. The evidence appears to rule out explanations ascribing such diaphragms to an optical artifact. More detailed description is given of a component of the pore complex only briefly described heretofore and now called the “intracisternal ring.” The varied results and interpretations of studies of the pore complex in various cells are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460105
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  • 37
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    Electromyography and mechanics of mastication in the albino rat (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 1-33 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The masticatory apparatus in the albino rat was studied by means of electromyography and subsequent estimation of muscular forces.The activity patterns of the trigeminal and suprahyoid musculature and the mandibular movements were recorded simultaneously during feeding. The relative forces of the individual muscles in the different stages of chewing cycles and biting were estimated on the basis of their physiological cross sections and their activity levels, as measured from integrated electromyograms. Workinglines and moment arms of these muscles were determined for different jaw positions.In the anteriorly directed masticatory grinding stroke the resultants of the muscle forces at each side are identical; they direct anteriorly, dorsally and slightly lingually and pass along the lateral side of the second molar. Almost the entire muscular resultant force is transmitted to the molars while the temporo-mandibular joint remains unloaded. A small transverse force, produced by the tense symphyseal cruciate ligaments balances the couple of muscle resultant and molar reaction force in the transverse plane. After each grinding stroke the mandible is repositioned for the next stroke by the overlapping actions of three muscle groups: the pterygoids and suprahyoids produce depression and forward shift, the suprahyoids and temporal backward shift and elevation of the mandible while the subsequent co-operation of the temporal and masseter causes final closure of the mouth and starting of the forward grinding movement. All muscles act in a bilaterally symmetrical fashion.The pterygoids contract more strongly, the masseter more weakly during biting than during chewing. The wide gape shifts the resultant of the muscle forces more vertically and more posteriorly. The joint then becomes strongly loaded because the reaction forces are applied far anteriorly on the incisors. The characteristic angle between the almost horizontal biting force and the surface of the food pellet indicates that the lower incisors produce a chisel-like action.Tooth structure reflects chewing and biting forces. The transverse molar lamellae lie about parallel to the chewing forces whereas perpendicular loading of the occlusal surfaces is achieved by their inclination in the transverse plane. The incisors are loaded approximately parallel to their longitudinal axis, placement that avoids bending forces during biting. It is suggested that a predominantly protrusive musculature favors the effective force transmission to the lower incisors, required for gnawing. By grinding food across transversely oriented molar ridges the protrusive components of the muscles would be utilized best. From the relative weights of the masticatory muscles and their topographical relations with joints, molars and incisors it may be concluded that the masticatory apparatus is a construction adapted to optimal transmission of force from muscles to teeth.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051460102
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460201
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    Molting in stomatopod crustaceans. I. Stages of the molt cycle, setagenesis, and morphology (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 55-80 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The description of stages of the molt cycle in mantis shrimp (emphasizing Gonodactylus but compared in a number of Gonodactylidae, Squillidae, and Lysiosquillidae) includes data on texture, hardness, and color of the exoskeleton; behavior; and the micromorphology of the integument and developing setae.After stage A1, When the exoskeleton feels soft and soapy, and A2, when the abdomen attains parchment consistency, the exoskeleton continues to harden until stage C1, when the telson carinae can no longer be depressed with a fingernail. The propodus (C2) and the merus (C3) of the raptorial appendage are the last elements to become rigid. The meral spot achieves indistinct coloration at B1 and distinct but pale coloration at B2; body color continues to intensify until C4.Changes in behavior are particularly marked before and after the molt. After the molt defensive and avoidance behaviors characterize A1 and A2. Threatening increases from low to intense levels in A2 and B1. Striking and offensive behavior increase from weak to normal intensities from B2 to C4. One or two days before the molt, animals lower activity and dominance and feeding levels, exhibit reclusive behavior, and sometimes seal the cavity entrance.The morphology of setagenesis is particularly valuable for determining the stage of the molt after the exoskeleton hardens. The ratio of setae containing cellular contents throughout the lumen to those condensed into strands separates stages A2 through C3. “Cones,” although variable within and between individuals in some species, form initially in B2 and continue to condense through D. Initiation of C4, D0 and D1 overlaps variously in some individuals. Apolysis (D0) and morphogenesis of new setae (D1-D3) provide cues for identifying approach of the molt. Setagenesis and setal morphology differ among families, genera and some species of stomatopods. The structure and functional morphology of setae can be explained by the form of setagenesis.Passive swelling and active muscular peristalsis effect the shedding of the exoskeleton and setal eversion at the molt. The carapace and rostrum are shed as one unit. Patterns of meral sutures vary among taxa with enlargement of the merus and with subterminal or terminal ischiomeral articulation. Middorsal sutures open only on the sixth and seventh thoracic segments, suggesting loss of the first rather than the last abdominal segment and therefore a distant relationship to other eumalacostracans.Approximate durations of the molt stages in stomatopods are compared to those of 11 crustacean taxa. Extensive overlap seems to occur among midinterval stages, particularly in stomatopods. The developmental plateau occurs in different stages in different taxa. Late postmolt (C), associated with calcification, requires longer in more heavily calcified than in thinly calcified species, except for stomatopods. The physiological events immediately surrounding the the molt (A1-B1 and D3-D4) are compressed in time in crayfish, brachyurans, and especially in stomatopods. Behavioral adaptations maximize this compression of physiological events at the molt in stomatopods. These three groups also possess the most asymmetrical molt cycles of the crustacean taxa examined. It is hypothesized that these modifications of the molt cycle allow opportunistic molting and represent adaptations to agonistic behavior.Temporal variation in behavior and in color over the molt cycle may increase the potential for speciation by processes resembling neoteny.
    Additional Material: 25 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051460104
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    Structure development and evolution of the male pheromone system in some noctuidae (Lepidoptera) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 129-175 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Pheromone systems from seven species of noctuid are examined. Much of the structure of scales from the wings and/or the abdomen is interpreted as a modification for secretion or release of a pheromone. Scales with an extremely complex surface provide a large evaporation surface, while those connected to secretory cells show less superficial folding than body-covering scales.The development of the secretory gland and diseminatory scales in Mamestra configurata is followed from the exuvial pharate adult stage to emergence. Both components are paired and develop from epidermal cells lining a pair of large lateral invaginations. They may have resulted through division of a group of less specialized cells that originally combined the function of pheromone production and release.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/jmor.1051460107
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    Relationship of the sarcoplasmic reticulum to fibril and triadic junction development in skeletal muscle fibers of fetal monkeys and humans (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 97-127 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Examinations of stages of fibril development in muscle fibers of seven Rhesus monkey and six human fetuses reveal SR tubules encircling the Z lines at all stages of fibril development. The encircling SR tubules are continuous with the SR network of tubules which is found surrounding fibrils at all stages of development observed. The SR tubules encircling the Z lines show connections (electron-opaque strands) with the Z lines. The developing triadic junction shows a progressive increase in complexity of structures within the junction. First, membranes of T and SR become apposed with no visible structure between them. Second, tenuous connections are found traversing the space between apposed membranes. Third, well developed bridges are seen traversing the space. And finally, an intermediate density midway between the apposed membranes and parallel to them is found in favorable sections. Junctions between T tubule membranes were also observed and the structures in these junctions are somewhat similar to those found in junctions between T and SR membranes. The change in orientation of triads from predominantly longitudinal to predominantly transverse is complete in the 18-week monkey fetus and incomplete in the latest stage (28-week) of fetal development observed in humans.
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    URL: http://dx.doi.org/10.1002/jmor.1051460106
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  • 42
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    The maxillary palp organs of a wood-boring beetle, Melittomma sericeum (coleoptera, lymexylonidae) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 123-135 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The complex and conspicuous basket-like structure attached to the third segment of each maxillary palp of Melittomma sericeum males is densely covered with tactile hairs on its outer or convex surface and with thinwalled chemoreceptors on its inner or concave surface. In a living male the structure is highly mobile and is extended laterally and ventrally. It evidently serves to detect odors produced by the female.
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    URL: http://dx.doi.org/10.1002/jmor.1051470202
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  • 43
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    Smooth muscle cells in the rat testicular capsule: A developmental study (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 171-185 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study of the postnatal development (from 1 to 60 days) of smooth muscle elements in the rat testicular capsule has demonstrated that while such elements are identifiable by light microscopy at 30 days, myocytes are present at birth as seen by electron microscopy. The differentiation of smooth muscle from birth to 30 days has been described, by which time it is of adult morphology and content. Perhaps significantly, it is at 30 days that the testis achieves a scrotal position, although sexual maturity does not occur until about 60 days. Presumably, at 30 days the testicular capsule of the rat is capable of the spontaneous contractions which are known to occur in the adult and which are assumed to aid the transport of non-motile spermatozoa from the testis to the epididymis.The presence of occasional striated muscle fibers in the rat testicular capsule as reported previously has not been confirmed by this investigation, although their possible origin is discussed.
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    A histochemical study of cervical motor neurons and the posterior latissimus dorsi muscle in normal and dystrophic chickens (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 155-169 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A chromatolysis study, 14 to 21 days following denervation, showed the spinal cord representation of the nerve to the posterior latissimus dorsi muscle to be in the ventrolateral cell column between cervical ganglia 14 and 15. To characterize cervical neurons not undergoing chromatolysis, histochemical studies were done on the cords of additional nondenervated animals. Staining reactions for beta-hydroxybutyrate dehydrogenase, succinic dehydrogenase and cholinesterase did not reveal any quantitative differences between motor neurons in cervical segments 14 and 15 of normal and dystrophic birds. Motor neurons are positive for beta-hydroxybutyrate dehydrogenase and succinic dehydrogenase, but the surrounding neuropil is positive for the latter only. No pseudochlinesterase activity is found in the ventral horn cells, but true cholinesterase is present in most of the neurons. With the periodic acid-Schiff reaction the dystrophic cords exhibit many neurons with large amounts of glycogen in them. Normal cords examined show either no glycogen positive cells or an occasional ventral horn cell with much glycogen in it. Normal muscles contain less succinic dehydrogenase and beta-hydroxybutyrate dehydrogenase positive fibers than dystrophic muscle. More periodic acid-Schiff positive fibers are present in normal muscles than in dystrophic muscle. The motor endplates in normal muscle contain only true cholinesterase. Both true and pseudocholinesterase activity is present in the motor endplates of dystrophic muscle.
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    URL: http://dx.doi.org/10.1002/jmor.1051470204
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    The feeding system of terrestrial tiger salamanders (Ambystoma tigrinum melanostictum baird) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 137-153 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: High speed cinematography was used to record the feeding activities of terrestrial Ambystoma tigrinum melanostictum. A description of these activities based on films of more than 50 feeding sequences is presented, and the mechanical units involved are defined, described, and functionally analyzed. Evolutionary implications of the feeding system are discussed.In a typical feeding sequence, A. t. melanostictum stations and maintains its lower jaw 3-5 mm from the prey. The mouth is then opened to form a gape of ∼60° by raising the anterior end of the flexed skull and by elevating and advancing the trunk while the mental symphysis of the lower jaw remains stationary. As the mouth opens the bulging tongue is recontoured so that the posterior glandular region becomes the tip of the fully protruded tongue, which may extend 3 to 7 mm beyond the symphysis. Dorsally the protruded tongue has a deep central depression and pronounced anterolateral rims. The anterior rim collapses on contact, thereby engulfing the prey in a sticky trough that retains it during tongue withdrawal. The cervical region is then flexed and the skull snaps downward. If the prey resists the tongue and is captured by marginal teeth, A. t. melanostictum relies on repeated tongue protraction and retraction, in some cases accompanied by inertial feeding. Swallowing involves gular expansion and contraction, and is accompanied by eye depression. When the mouth is opened during ingestive activities, the lower jaw remains in place.Apparently, A. t. melanostictum uses the dorsal trunk, the cucullaris major and the robust heads of the depressor mandibulae muscles to open the mouth. During skull elevation the lower jaw is partially immobilized by the geniohyoideus, and rectus cervicis superficialis muscles. The subarcualis rectus I muscles are prime movers in tongue projection. Hebosteoypsiloideus muscles assist in tongue protrusion by slackening the rectus cervicis profundus muscles that would otherwise restrict anterior displacement of the otoglossal cartilage and copula. Tongue contouring is performed by the complex genioglossus musculature. Sublingual and anterolingual sinuses facilitate protrusion and contouring by providing space and lubrication. Rectus cervicis muscles (profundus and superficialis) are responsible for tongue withdrawal. Closure of the mouth is accomplished by the four levator mandibulae muscles, and again the lower jaw is immobilized, mostly by ventral longitudinal muscles.Skull-trunk elevation during prey capture and ingestion was also observed and filmed in several other species of Ambystoma, in Dicamptodon ensatus, and in two salamandrid species. Apparently raising and straightening the craniovertebral axis, while the mental symphysis retains contact with the substratum, is a common feature of urodele feeding systems, and does not require peculiar morphological adaptations.
    Additional Material: 6 Ill.
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    Evolution of the mammalian middle ear (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 403-437 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure and evolution of the mandible, suspensorium, and stapes of mammal-like reptiles and early mammals are examined in an attempt to determine how, why, and when in phylogeny the precursors of the mammalian tympanic bone, malleus, and incus (postdentary jaw elements and quadrate) came to function in the reception of air-borne sound. The following conclusions are reached.It is possible that at no stage in mammalian phylogeny was there a middle ear similar to that of “typical” living reptiles, with a postquadrate tympanic membrane contacted by an extrastapes. The squamosal sulcus of cynodonts and other therapsids, usually thought to have housed a long external acoustic meatus, possibly held a depressor mandibulae muscle.In therapsids an air-filled chamber (recessus mandibularis of Westoll) extended deep to the reflected lamina and into the depression (external fossa) on the outer aspect of the angular element. A similar chamber was present in sphenacodontids but pterygoideus musculature occupied the small external fossa. The thin tissues superficial to the recessus mandibularis served as eardrum. Primitively, vibrations reached the stapes mainly via the anterior hyoid cornu, but in dicynodonts therocephalians, and cynodonts, vibrations passed mainly or exclusively from mandible to quadrate to stapes and the reflected lamina was a component of the eardrum.In the therapsid phase of mammalian phylogeny, auditory adaptation was an important aspect of jaw evolution. Auditory efficiency, and sensitivity to higher sound frequencies, were enhanced by diminution and loosening of the postdentary elements and quadrate, along with transference of musculature from postdentary elements to the dentary. These changes were made possible by associated modifications, including posterior expansion of the dentary. Establishment of a dentray-squamosal articulation permitted continuation of these trends, leading to the definitive mammalian condition, with no major change in auditory mechanism except that in most mammals (not monotremes) the angular, as tympanic, eventually became a non-vibrating structure.
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    URL: http://dx.doi.org/10.1002/jmor.1051470404
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    Evidence for a structural relationship between successive parallel tubules in the SR network and supernumerary striations of Z line material in purkinje fibers of the chicken, sheep, dog and rhesus monkey heart (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 459-473 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The striations and the intervening filaments observed in the present study have been variously designated in the literature as: prodromal pattern, leptomeric myofibril, microladder, leptomeric organelle, leptofibril and zebra body. Electron microscope examinations of Purkinje fibers from the septa, papillaries, trabeculae carneae and small endocardial strands from chicken, sheep, dog and monkey hearts have revealed a close association between densely stained striations of supernumerary Z line material and successive parallel tubules in the network formed by the sarcoplasmic reticulum (SR). The striations appear to be linked together by filaments that somewhat resemble the part of thin filaments attached to Z lines in normal fibrils. The evidence for a close association of striations and SR tubules is derived from a similarity of spacing between striations and successive parallel tubules in the SR network and from a resemblance of striation and SR network patterns. The evidence for a structural relationship between striations and SR tubules is derived from the observation of electron-opaque strands traversing the space between striations and SR tubules.
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    URL: http://dx.doi.org/10.1002/jmor.1051470406
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    Dynamics and acoustical radiation of Porichthys notatus' swim bladder system (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 327-335 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The swimbladder system of the plainfin midshipman consists of a gas-filled bladder and two intrinsic sonic muscles which are attached to the bladder at opposite sides. An experimental and analytical study was conducted to define the physical characteristics of this dynamic system, and to relate these characteristics to radiated acoustical pressure pulses. Results indicate that the system has two degrees of freedom, being comprised of two inertial, stiffness and damping components; the first and second mode components of a 23.1-centimeter midshipman are 0.002 and 0.019 kg (inertial) 2130 and 106,000 newtons per meter (stiffness) and 0.25 and 0.10 (damping) respectively. This system is excited by the sonic muscle forcing function which equals \documentclass{article}\pagestyle{empty}\begin{document}$ 0.00236{\rm}\sin \frac{{2\pi {\rm t}}}{{0.0045{\rm}\sec}}{\rm newtons}. $\end{document}Two system frequency response peaks were observed; the first was 110 hertz, at the flat section next to the sonic muscle, and was very near the repetition frequency of the sonic muscle pulses; the second was 350 hertz, at the hemispherical section, which was the frequency of the acoustical pressure pulse. These phenomena describe a dynamical system closely “tuned” to its forcing function, and a system which is highly responsive to acoustical pressure pulses radiated by neighboring midshipmen. The acoustical pressure pulse coincides in wave form with the hemispherical bladder wall acceleration.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051450306
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    Mitochondrial changes in flight muscles of normal and flightless Drosophila melanogaster with age (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 337-353 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fine structural changes in mitochondrial morphology pertaining to size, number and growth were examined in flight muscles of normal and experimentally dewinged male Drosphila melanogaster ranging up to 26 days of age. In the normal winged flies, the number of mitochondria decreases during the first week of adult life whereas the size of individual mitochondrial profile increases significantly. Changes in mitochondrial size and number are due to the fusion of mitochondria. Fused mitochondria are extremely large in size and irregular in shape. In 26-day old normal flies, the number of mitochondria increases while the mitochondrial size is reduced indicating mitochondrial division. In comparison to the normal flies, dewinged flies exhibit a similar degree of mitochondrial fusion and growth during the first week of life. However, the extent of mitochondrial fission in 26-day old dewinged flies is greater than in the normal flies of this age. Structural mechanisms of mitochondrial fusion and fission are described. The objective of this study was to examine the relative effects of age and flight activity on the mitochondria.
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    URL: http://dx.doi.org/10.1002/jmor.1051450307
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    A Golgi study of the optic tectum of the Tegu lizard, Tupinambis nigropunctatus (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 215-227 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The dendritic patterns of cells in the optic tectum of the tegu lizard, Tupinambis nigropunctatus, were analyzed with the Ramon-Moliner modification of the Golgi-Cox technique. Cell types were compared with those described by other authors in the tectum of other reptiles; particular comparisons of our results were made with the description of cell types in the chameleon (Ramón, 1896), as the latter is the most complete analysis in the literature. The periventricular gray layers 3 and 5 consist primarily of two cell types  -  piriform or pyramidal shaped cells and horizontal cells. Cells in the medial portion of the tectum, in an area coextensive with the bilateral spinal projection zone, possess dendrites that extend across the midline. The latter cells have either fusiform or pyramidal shaped somas. The central white zone, layer 6, contains fibers, large fusiform or pyramidal shaped cells, fusiform cells, and small horizontal cells. The central gray zone, layer 7, is composed predominantly of fusiform cells which have dendrites extending to the superficial optic layers, large polygonal cells, and horizontal cells. The superficial gray and white layers, layers 8-13, contain polygonal, fusiform, stellate, and horizontal elements. Layer 14 is composed solely of afferent optic tract fibers.Several differences in the occurrence and distribution of cell types between the tegu and the other reptiles studied are noted. Additionally, the laminar distribution of retinal, tectotectal, telencephalic, and spinal projections in the tegutectum can be related to the distribution of cell types, and those cells which may be postsynaptic to specific inputs can be identified. The highly differentiated laminar structure of the reptilian optic tectum, both in regard to cell type and to afferent and efferent connections, may serve as a model for studying some functional properties of lamination common to cortical structures.
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    URL: http://dx.doi.org/10.1002/jmor.1051460204
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460301
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    Post embryonic development of the central nervous system of the spider Argiope aurantia (Lucas)This paper is dedicated to the memory of Prof. K. Pampapathi Rao on the first anniversary of his death. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 325-342 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Volumetric and histological changes of the central nervous system were studied during post embryonic development of a spider, Argiope aurantia.The neural mass of Argiope grows allometrically with respect to volume of the cephalothorax and body weight. In the first instar 46% of the cephalothoracic volume constitutes the neural mass and this is reduced to 4% in the female (9th stage) and 12% in the male (7th stage) spider.Growth curves for the cephalic ganglion, measured at all stages, represent a straight line. The neural mass of females is two and a half times larger than that of the males. The ganglion increased 24 fold in female and 10 fold in male spiders. Addition of neural mass occurs in all stages.The brain volume is greater than that of the subesophageal ganglion in the first two instars. In subsequent stadia, the subesophageal ganglion grows faster, and in females it is finally three times and in males two times larger than the brain.Growth of cortex and neuropile depict exponential curves. Comparison of growth patterns of these shows an inverse relationship during development. While the volume of the cortex is higher in the first two or three stages, the volume of the neuropile is higher in the remaining stadia. The causes for this growth pattern are discussed.Counts of cell numbers show that there is a constant population of neurons throughout the post-embryonic development. The number of nerve cells in females is higher than in males, 11% in the subesophageal ganglion and 58% in the brain.The growth of the cortex is partly accomplished by an increase in cell volume. In male and female spiders the increase in Type-B cells is 20 and 50 fold, while that of large motor neurons is 200 and 600 fold respectively. The motor neurons of 20 μ and above number 63 in male and 916 in female adult spiders.The growth of neuropile occurs through an increase of dendritic arborization and axonal branching. The largest axons measure 1 μ in the first and 16 μ in adult stages. An increase of incoming sensory fibers is also noticed during development.Invasion of neural lamella into cortex and neuropile increases during development. Neural lamella which are 1-2 μ in the first stage grow to 40-100 μ thickness in adult female spiders, near the origin of the main nerves. One type of astral cells, counted in neuropile, increases 10 fold.The appearance of a central body and the beginning of web construction coincide during the second instar. The relationship between these two is discussed.
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    URL: http://dx.doi.org/10.1002/jmor.1051460303
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    Auditory systems of Heteromyidae: Functional morphology and evolution of the middle ear (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 343-376 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Middle ears (515) from 26 species of the rodent family Heteromyidae  -  genera Dipodomys, Microdipodops, Perognathus, and Liomys  - were studied both grossly and histologically, for qualitative and quantitative comparisons. Middle ear modifications characteristic of each genus are qualitatively described. Quantitative comparisons are made among the 26 species in the study. Some correlations between middle ear size and other measurements are discussed.The middle ear is an acoustical transformer that for best efficiency must match the impedance of the cochlea to the impedance of the air in the external auditory meatus. It accomplishes this by a pressure increase and a velocity decrease through the combined effects of the lever and areal ratios; however, because the important consideration is a matching of two impedances rather than an absolute pressure increase, the pressure transformer ratio is a less informative measure of the middle ear's efficiency than is the impedance transform ratio. The impedance transformer mechanism is explained (from a morphological point of view), and equations are presented. Dipodomys, Microdipodops, and Perognathus have a theoretical transmission (at the resonant frequency) of 94-100% of the incident acoustical energy; Liomys, 78-80%. The areal ratio of stapes footplate to 2/3 tympanic membrane is remarkably constant among the species, varying only from 0.04 to 0.07: in Dipodomys and Microdipodops this small ratio is due to the very large tympanic membrane; in Perognathus and Liomys it is due to the extremely small stapes footplate. The lever ratio of incus to malleus varies from 0.28 to 0.33 in Dipodomys and Microdipodops, from 0.37 to 0.46 in Perognathus, and from 0.55 to 0.60 in Liomys. In addition, the middle ear volumes and the morphology of tympanic membrane, ossicles, ligaments, and muscles, all combine to minimize both mass and stiffness. All these data suggest middle ear mechanisms which are very efficient over a broad frequency range.The middle ear modifications found in heteromyids are adaptive in predator avoidance, especially in areas of little natural cover; nevertheless, contrary to expectations, there is no firm relationship between habitat and the extent of these modifications in the 26 species. However, environment did apparently play an important role in the evolution of the family, and this is discussed.
    Additional Material: 31 Ill.
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    Auditory systems of Heteromyidae: Postnatal development of the ear of Dipodomys merriamiThis research was supported in part by grants NS-05800 and NS-11459 from National Institutes of Health. The author appreciates the assistance of M. Webster. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 377-393 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Serial histological sections of kangaroo rats of postnatal ages 0-, 3-, 7-, 10-, and 14-days were prepared and studied. At birth the middle ear is mostly filled with mesenchyme and small in size, having only a small hypotympanum and a very small epitympanic recess. During the first postnatal two weeks, much of the hypertrophy found in the adult middle ear develops. Because an entotympanic element is never formed, the previously called entotympanic chamber is here renamed the hypotympanum. The epitympanic recess greatly expands to form what has been called the dorsal (or anterior) mastoid sinus. Since this chamber has no relation to the mastoid, it is here renamed the epitympanum. Posteriorly, the previously called posterior mastoid sinus develops from the growth of the hypotympanum into and beyond the region of the posterior and horizontal semicircular canals. In development and adult position it is comparable to the primate antrum and so is here renamed the antrum.At birth the organ of Corti is very immature but its major cell types can be identified. During the first two weeks of development the following events occur: (1) the vas spirale disappears, (2) the inner spiral sulcus cells atrophy, (3) the hair cells and supporting cells mature, (4) the cells of Hensen differentiate with their apical processes elevating the reticular lamina, (5) the innermost cell of Claudius migrates under and supports the Hensen's cells, and (6) the hyaline mass of the zona pectinata of the basilar membrane loses its connective tissue cells and expands in size. The developmental events support the previous description and identification of Hensen's and Claudius' cells.
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470201
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    Development of the head skeleton and pectoral girdle in Esox (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 61-88 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A consideration of head development in two species of Esox, lucius and americanus (ssp. vermiculatus) representing the two subgenera Esox and Kenozoa respectively, focused on the significance of the variations of the latero-sensory canal system, its associated bones, and other skeletal elements. In living forms only aspects of “regression” or specialization can be studied. Canals tend to be reduced to pit lines first at their termini but can be broken in their course. Pit lines range from nearly canals to surface structures, or even fail to develop. The number of neuromasts varies. Canal bones develop from two centers: neuromast related and deeper membranous centers which may have no relationship to neuromasts. Tooth-bearing and non-canal-related dermal bones have only membranous (original) centers. The number of neuromasts associated with a bone usually does not affect its development or form. In the case of the circumorbital bones, the extrascapulars, and the nasal, a one to one relationship has developed by regression - towards the development of the latero-sensory component only. The idea that reductions in bone number are commonly traceable to fusion is rejected although examples of fusion are known. Most bones that disappear are simply lost (no blastema or other evidence of their presence seen in development). The relationship between dermal bone and chondral bone is examined and there is evidence of the former giving rise to the latter. The ontogenic order of appearances shows a feeding (functional) correlation.
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    Organization of the teleostean nucleus rotundus (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 89-107 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The nucleus rotundus of 21 species of teleosts was studied by a modified Bodian and the Golgi method to clarify the histological organization, with special reference to the cell lamination and the glomerular formation.The common components of the nucleus in all species are as follows: a thick fiber bundle which comes from the commissura horizontalis and enters the nucleus from the dorsal surface, many small cells, large cells, glomeruli, and a surrounding fibrous capsule. The nuclei of all species studied are classified into three types mainly on the distribution of the small cells, and to a lesser degree on the location of the large cells and the glomeruli.The first type of nucleus has small cells. large cells and glomeruli throughout its extent. In the second type of nucleus, many small cells form a peripheral cell layer, while the large cells and glomeruli are found all over the nucleus.The third type of nucleus is clearly laminated. It is composed of four layers arranged concentrically around a central fiber net in the following order: a glomerular layer, a fibrous layer, a small-cell layer, and a peripheral fibrous capsule. In some species, the large cells are located in the fibrous capsule, and all glomeruli contain a star-like structure, which corresponds to the tips of the large cell dendrites.
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    Morphology of lymphoid organs in a cichlid teleost, Tilapia mossambica (Peters)Supported in part by a grant (01-077) from the U. S. National Institutes of Health, under special foreign currency research program (PL-480). (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 109-121 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In Tilapia mossambica organized lymphoid tissues are present in the thymus, head-kidney and spleen, whereas they are lacking in pericardial tissue, liver, mesonephros, intestine and rectum. No lymphoid tissue was observed in the chondrocranium and cartilaginous viscerocranium of young adults.The thymus in Tilapia is encapsulated by thin strands of collagen fibers and consists of outer, middle and inner zones. While middle and inner zones are comparable to the thymic cortex and medulla of higher vertebrates, the homology of the outer zone is not clear. At the anterior end of the thymus, a loose aggregation of lymphocytes without a definite boundary has been observed.The head-kidney is characterized by the presence of lymphoid follicles, a subcapsular sinus, a hilus-like area and lymphatic vessels. The spleen is grossly divisible into white pulp and red pulp; the white pulp contains only a reticular area without definite lymphoid centers and the latter contains predominantly erythrocytes. Morphological changes in the lymphoid organs associated with immune response have been discussed.
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    Structure and function of the head in flabelligerid polychaetesMost of this material forms a portion of a dissertation submitted to the faculty of the University of Southern California in partial fulfillment of the requirements for the Ph.D. degree. Contribution number 16 from the Santa Catalina Marine Biological Laboratory. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 187-207 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The functional anatomy of the head of Flabelliderma commensalis is described and compared to other flabelligerid polychaetes. Prostomial parts include the dorsal lip, the palps, two pairs of nuchal organs, four eyes and the prostomial lobe and ridge. The eyes are inverse pigment cup types with the medial portions of the sensory cells expanded to form a clear lens-like body. Peristomial parts include the median and ventral lips, the branchial membrane and the branchiae. The derivation of the nephridiopore is unknown. The spiraled branchiae of Coppingeria and the gill books of Diplocirrus are newly described variations in branchial structure. The head is retractable in some species and the anterior setigers are modified to form a protective setal cage. Two methods are employed for feeding: one for host fecal pellets and the other for detrital materials. Chemoreception, respiration, feeding and cleaning rely on a complex pattern of ciliary currents.
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    A reconsideration of the phylogeny of the tetrapod heart (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 209-228 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: After dissecting a variety of vertebrate hearts and extensively reviewing the literature, I have drawn some conclusions concerning the phylogeny of the tetrapod heart that differ from commonly expressed viewpoints in the literature. It is probable that the absence of an interventricular septum in amphibians is a primitive feature (rather than representing a loss). The complete interventricular septum of crocodilians and birds probably evolved primarily from the major horizontal septum of the typical (noncrocodilian) reptilian heart, with a smaller part representing a new development. The interventricular septum of mammals probably also evolved primarily from the reptilian horizontal septum. There is no reason to assume that the mammalian heart and aortic arches evolved directly from a pre-reptilian stage, as is often assumed. The evidence upon which these conclusions are based is given.
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470301
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    Trophotaeniae, embryonic adaptations, in the viviparous ophidioid fish, Oligopus Longhursti: A study of museum specimensContribution No. 37 of the New York Ocean Science Laboratory. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 385-401 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Prepartum embryos obtained from old museum specimens of the ovo-viviparous fish, Oligopus longhursti, possess external intestinal appendages. They are structurally identical to the trophotaeniae described by Turner ('37) and Mendoza ('37) in goodeid fishes. This is the first report of trophotaeniae in the viviparous ophidioids. Two developmental Stages, A and B, were observed. A is a tailbud stage, 2.0-2.25 mm in length, and B is a finfold embryo, 3.0-3.25 mm in length (Wourms and Bayne, '73). Trophotaeniae occur in the form of a single median anterior process and a pair of median posterior processes. They originate from a conspicuous peduncle formed around the anus. The processes of stage A are 1.5-2.0 mm long, 0.05 mm in diameter at their base and 0.04 mm at their tip. The stage B processes are 2.75-3.00 mm long, 0.075 mm in diameter at their base and 0.050 mm at their tip. Serial sections show that the surface epithelium of the trophotaeniae is continuous with and identical to the surface epithelium of the trophotaeniae is continuous with and identical to the surface epithelium of the embryonic gut. Examination both by transmission and scanning electron microscopy confirms that the apical surface of the trophotaenial epithelium and intestinal epithelium are covered with microvilli. Trophotaeniae are considered to function in the uptake of nutrients since they are structurally identical to intestinal epithelial cells. We suggest that maternal nutrients absorbed by trophotaeniae rather than yolk reserves are the principal source of embryonic metabolites. Trophotaeniae may afford a selective advantage since their existence in O. longhursti maximizes the number of large size embryos which a female can produce at one time. Occurrence of trophotaeniae in ophidioid, goodeid and zoarcid embryos is a remarkable example of convergent evolution.
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    Oocyte differentiation in Urechis caupo (echiura): A fine structural study (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 475-505 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The fine structure of oocytes of Urechis caupo is described for seven arbitrary stages ranging from the smallest oocytes (7μm in diameter) in the coelom to the mature oocytes (115 μm in diameter) in the storage organs. Although most types of cytoplasmic organelles accumulate more or less continuously, yolk granules do not appear until oocytes reach a diameter of 35 μm, and there is stage-specific synthesis of cortical granules in 60-80 μm oocytes. In the nucleus a single nucleolus first appears when an oocyte is 15 μm in diameter. Then a nucleolus satellite, which is about 3 μm in diameter, forms in 30 μm oocytes; this nucleolus satellite later (60-70 μm oocytes) becomes surrounded by 750 nm dense spherical bodies. Large (2-4 μm in diameter) juxtachromosomal spherules occur only in the nuclei of mature oocytes. Microvilli become progressively more numerous and longer until the oocytes reaches a diameter of 90 μm their tips project 1 μm beyond the fibrous surface coat, which is 2 μm thick when well developed. Near the end of oocyte growth, the microvilli retract into the surface coat leaving their pinched-off tips adhering to the outside of the coat.
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    The long-term organ culture of tissues from adult Necturus maculosus, the mud puppy (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 319-325 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fragments of Necturus maculosus liver, spleen and kidney were cultured at 25°C in 50% Minimal Essential Medium (MEM) or 50% Leibovitz L-15 Medium (L-15) for up to 49 days. The integrity of tissue structure was evaluated, hepatocyte cell and nuclear volumes were measured, the respiration rates of freshly-isolated and cultured liver fragments were determined, and the mitotic incidences in cultured liver, spleen and kidney were estimated. The addition of adrenalin caused a reduction in the glycogen content of liver cultures, and the subsequent addition of insulin resulted in a net increase in glycogen synthesis. Glycogen levels fell in fragments cultured in L-15, but rose in cultures in MEM. Arginase and ornithine transcarbamylase levels fell gradually throughout a 49-day culture period in L-15. Evidence presented supports the position that the survival of tissues in vitro is related to cell size and respiration rate. These experiments show that N. maculosus is a suitable donor of tissues for long-term organ culture studies on the maintenance and control of tissue-type specific structure and function.
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    Neurosecretory system of the American dog tick, Dermacentor variabilis (Acari: Ixodidae). II. Distribution of secretory cell types, axonal pathways and putative neurohemal-neuroendocrine associations; comparative histological and anatomical implicationsIn part, from a dissertation by the senior author submitted in partial fulfillment of requirements for the Ph. D. degree in Entomology, The Ohio State University, Columbus. Supported by NIH Training Grant 5 T01 AI 00216 through the Acarology Laboratory, The Ohio State University.Supported in part by Public Health Service Research Grant AI-09556 from the National Institute of Allergy and Infectious Diseases (Principal Investigator, J. H. Oliver, Jr). (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 269-293 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Histological observations using specialized techniques reveal neurosecretory cells in 18 centers throughout the rind (cortex) of the central nerve mass or synganglion of Dermacentor variabilis. Many cells contribute to complicated networks of neurosecretory pathways and tracts in pre- and post-esophageal portions of the synganglion. The four types of neurohemal-neuroendocrine associations found in Dermacentor resemble structures found in soft ticks (Argasidae) and in other Arachnida, but are more diverse than those described from any other single species. Neurosecretory terminals are distributed diffusely and in two concentrated associations within the perineurium of the synganglion and major peripheral nerves. Terminals are also distributed in the perineurial layers of lateral segmental organs which lie in the general hemocoel at the level of the pedal nerves. A retrocerebral organ complex surrounds the esophagus at its junction with the midgut. The complex includes dorsal and ventro-lateral lobes (containing neurosecretory terminals and intrinsic secretory cells) and the proventricular (neurohemal) plexus. This plexus seems to be a modified (concentrated) cardioglial association. Cardioglial associations are also formed by the neurosecretory innervation of vascular walls of the dorsal aorta and circulatory sinuses which envelope the synganglion and major peripheral nerves. Inferential considerations of neurosecretory and endocrine interactions in the Acari are based on these anatomical and histological data which also provide the basis for evolutionary considerations of anatomical relationships and specializations in the neurosecretory systems of other Arachnida.
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051450401
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    Muscle activity in rat locomotion: Movement analysis and electromyography of the flexors and extensors of the elbowPortions of this study were reported on at the 1974 meetings of the American Association of Anatomists in Cleveland, Ohio. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 177-196 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Footfall patterns and time sequence of activity are described for white rats conditioned to run freely in an activity wheel (which they drive). Motion is described in terms of soft contact, hard contact, soft contact, and flip phases. Duration of stride decreases and length of stride increases from walk to trot to canter to gallop. Myographic analysis shows that the brachialis has a major tonic function after it fires strongly during the flip phase and during much of the hard contact phase. Animals running at canter or gallop show major asymmetries between forelimb muscles on the first paw and on the lead paw sides.
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    Cytological events leading to the cleavage of golden hamster zygotes (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 197-213 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fertilized golden hamster eggs were examined between 6 and 20 hours post-ovulation to determine the events leading to the two-cell stage. Following their migration the pronuclei remain in the central region of the zygote for approximately ten hours. The morphologically, indistinguishable male and female pronuclei remain relatively unchanged during this period, i.e., they do not interdigitate or fuse with one another as described for the zygotes of other organisms. Following this period and at the time of pronuclear breakdown elongate vesicles appear along the nucleoplasmic surface of the pronuclear envelopes. Later the pronuclear envelopes fragment into elongate cisternae; these and the vesicles formed along the inner lamina of the pronuclear envelopes remain closely associated and constitute quadrilaminar structures. The chromosomes which condense prior to and during pronuclear envelope breakdown, migrate to the equatorial plate of the forming cleavage spindle. After cytokinesis the chromosomes in the blastomere nuclei disperse. Increase in the nuclear envelope to accomodate this dispersion may involve the addition of membrane from the quadrilaminar structures.
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    Aspects of germinal cyst and sperm development in Poecilia latipinna (Teleostei: Poeciliidae) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 229-249 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of the testis of Poecilia latipinna is described with particular reference to Sertoli cell-germ cell relationships during development and maturation of the germinal cyst. The cyst develops when primary spermatocytes become surrounded by a single layer of Sertoli cells at the testis periphery. As spermatogenesis and then spermiogenesis proceed, the cyst moves centrally in the testis toward the ducts comprising the vasa efferentia. In addition to being a structural part of the germinal cyst, the Sertoli cells phagocytize residual bodies cast off by developing spermatids and form an association with mature sperm, which resembles that observed in mammals, before the sperm are released into the vasa efferentia as a spermatozeugmata.The results of this investigation are discussed in view of what is known concerning testis structure in other teleosts and similarities between cell functions in teleosts and mammals. It is concluded that teleost Sertoli cells, teleost lobule boundary cells and mammalian Sertoli cells are homologous.
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    External morphology of antennae and their sense organs in the roach Gromphadorhina brunneri (Blattoidea: Dictyoptera)This investigation was supported by DeutscheForschungsgemeinschaft. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 251-263 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The antennae and their sense organs in nymphs and adult roaches of Gromphadorhina brunneri, were investigated and described. The number of segments and sensillae of the nymphal antennae depend on the developmental stage. Sexual dimorphism is pronounced. Males have longer antennae than females as well as an abundance of especially long sensory hairs (long wavy hairs), which are probably responsible for the perception of female sex pheromones. They also have more thin-walled sensory hairs, for instance, sensilla trichodea. On a morphological basis the sensillae of Gromphadorhina brunneri, were named and classified. Long wavy hairs and large sensory hairs appear to be present also in a related species, G. portentosa, but are lacking in others. Their distribution on the antennae varies greatly from that in G. portentosa but their structure varies only slightly. These two types of sense organs are considered to be specialized forms of sensilla chaetica. They are contact chemoreceptors, as are two other types of sensilla chaetica. Furthermore, thin-walled chemoreceptors are present, such as sensilla trichodea, sensilla basiconica, sensilla coeloconica and a typical mechanoreceptor, the sensillum campaniformium.
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    Cytological differentiation in the uropygial gland (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 395-413 
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    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ultrastructural changes were studied in the cells undergoing secretory differentiation in zone I of the tubules of the uropygial gland of White Plymouth Rock chickens. A layer of basal cells and four secretory stages are recognized as the cells migrate from the periphery to the lumen of tubules and progressively elaborate a secretion product.Basal cells, containing rough endoplasmic reticulum and free ribosomes, rest on the basement membrane and are the source from which secretory cells arise. Dilated perinuclear cisternae and the proliferation of smooth endoplasmic reticulum in the form of vesicles, invaginated sacs and cusp-shaped cisternae indicate the onset of lipogenesis in stage I cells. The perinuclear cisternae are more dilated and the endoplasmic reticulum is composed of saccules and cisternae in stage II cells. Stage III cells are characterized by concentric lamellae of endoplasmic reticulum surrounding secretory droplets. Dilated cisternae of endoplasmic reticulum and secretory droplets both contain a reticular substance. The perinuclear cisternae of stage III cells have returned to normal dimensions. Large mature lucent secretory droplets, lined with electron-dense material, fill the cytoplasm of stage IV cells which degenerate and release their secretory product into the tubule lumen.Spherical membrane-bound compartments containing a mottled substance of moderate electron density occur in basal cells and all subsequent secretory stages. These mottled bodies are surrounded by saccules of endoplasmic reticulum in stage II cells and are intimately associated with secretory droplets in stage III cells, but there is no evidence that they give rise to secretory droplets and their role in secretory differentiation is unknown.
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051460401
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    The fine structure of the lateral ocellus of the dobsonfly larva (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 415-429 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The lateral ocelli of the dobsonfly (Protohermes grandis, Neuroptera) larva have been examined with light and electron microscopy. The larva has six ocelli on both sides of the head, each containing a single corneal lens. A conical crystalline body, of some 10-20 cells is situated immediately posterior to the lens. From 100 to 300 elongated retinular cells are arranged perpendicular to the crystalline body except at the innermost surface of the lens, where they are absent. The distal process of each retinular cell is enclosed by a tube-like rhabdom formed by the close association of microvilli from the same and adjacent distal processes. The distal process contains many mitochondria, multivesicular bodies, microtubles and pigment granules. In the dark-adapted ocellus the pigment granules are concentrated near the nucleus which lies under the rhabdomic layer. The granules diffuse toward the rhabdomic microvilli during light adaptation.Each retinular cell has a single axon, which extends from the ocellus as an ocellar nerve fiber into the optic lobe, where it frequently synapses upon second order neurons. In addition to these afferent synapses, there are two other synaptic combinations: (1) a feedback synapse from a second order neuron to a retinular axon, and (2) a synapse between second order neurons. These results suggest that photic signals reach the more proximal part of the brain via second order neurons after some degree of integration in the optic lobe.
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    URL: http://dx.doi.org/10.1002/jmor.1051460307
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    The epithelium of the gastro-intestinal tract of Polypterus senegalus (Pisces:Brachiopterygii) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 447-456 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscopic studies revealed ciliation of the epithelium of the entire gastro-intestinal tract of Polypterus. Acidophil cells were found in the different regions of the alimentary canal, including its derivatives (the lungs and hepato-pancreatic ducts). Compared to other primitive forms and modern teleosts, the extreme fusion of the intestinal caeca in Polypterus, the ciliation and the overall dispersion of acidophil cells may represent a special organization inherited from a palaeoniscoid ancestor. Attention is also drawn to a possible channel of early evolution and function of the stomach diverticulum.
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    URL: http://dx.doi.org/10.1002/jmor.1051460403
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    Regeneration of digits and forelimbs in the Kenyan reed frog Hyperolius viridiflavus ferniqueiContribution number 52 from the Amphibian Facility.Supported in part by grants from the Muscular Dystrophy Associations of America and NIH Grant No. 1 PO6 RR 00572 to George W. Nace. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 431-445 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Newly metamorphosed individuals of the Kenyan reed frog, Hyperolius viridiflavus ferniquei, are able completely to regenerate amputated digits, including the morphologically complex digital pad. The sequence of morphological events is very similar to that seen in the typical epimorphic regeneration of amphibian extremities. Amputated forearms typically produce hypomorphic spike regenerates. Despite the lack of underlying hand and digital structures, an apical “digital” pad commonly differentiates.
    Additional Material: 3 Ill.
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    The suspensorium of Ctenopoma acutirostre: A comparative functional analysis with Anabas testudineus (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 457-477 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The functional and structural aspects of the suspensorium of Ctenopoma acutirostre have been correlated with those of Anabas testudineus. The different parts of the suspensorium are described, as are the muscles that are functionally connected with the suspensorium. Functions were analyzed by observations on living specimens, and by measurements recorded from the movie films. The role played by various bones and muscles to carry out the functions (the respiration, the gulping, and the feeding) has been explained. The different bones and muscles have been considered as functional units which often are connected to form couplings. During the respiration in Ctenopoma the depression of the lower jaw is conducted by the levator operculiopercular apparatus-mandible coupling. The presence of this coupling is indicated by the presence of dorso-ventral movement of the operculum. A remarkable ventro-dorsal and antero-caudal movement in the urhyal during feeding shows in Ctenopoma the presence of the sternohyoideus-hyoid apparatus-interopercular-mandible coupling, which depresses the lower jaw. In Ctenopoma, the suspensorium takes part in respiration, gulping, and feeding, whereas in Anabas it is only involved in gulping and feeding. To carry out its functions, the suspensorium implies three articulations: palatocranial, craniohyomandibular, and quadratomandibular with the cranium and the lower jaw, respectively. Finally, the suspensorium has been analyzed as a part of the architectonic structure of the entire head by using a diagrammatic model (fig. 13) based on mutual influence, integration, and couplings.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051460404
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    Functional anatomy of the heart of the harbor porpoise, Phocaena phocaena (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 479-493 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Thirty-six harbor porpoises, Phocaena phocaena, were caught off the coast of Southern New Brunswick and Nova Scotia as part of a study of the biology and ecology of these animals. The formalin-preserved heart was examined first in situ, then measured and studied in detail. If the weight of the thick layer of blubber is discounted, the heart is heavy relative to the total body weight as may be expected in an animal capable of fast swimming, great agility and frequent emergence from the water to breathe. The shape of the heart, the relative size of atria and atrial appendages, the morphology of the ventricular septum, the thickness of the walls of the sinus and conus of the right ventricle and the anatomy of the pulmonary veins were found to be constant for this animal and unlike that of non-cetaceans. It is suggested that the absence of respiratory movements during diving may lead to these modifications of cardiac structure in an animal that is particularly well adapted to a totally aquatic existence.
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    URL: http://dx.doi.org/10.1002/jmor.1051460405
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  • 78
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    The motor units of cat medial gastrocnemius: Electrical and mechanical properties as a function of muscle length (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 495-512 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effects of changing muscle length on the mechanical properties of 89 motor units from adult cat medial gastrocnemius have been studied in eight experiments.Few differences were found between the effects of length on tetanic tension, twitch tension, twitch-tetanus ratio, twitch contraction time, twitch half relaxation time, rate of force development and electrical activity for fast contracting (twitch contraction time ≤ 45 msec) and slowly contracting ( 〉 45 msec) units. Those differences that did appear did not persist when these two groups were matched by tetanic tension. It is concluded that the biophysical mechanisms responsible for the changes in mechanical and electrical properties with length must be similar for fast and slow twitch units and not related to potential differences in their muscle fiber type.The effects of changing muscle length on the mechanical properties of the eight whole muscles suggest that changes in force output with length are of minor importance during normal movements as the muscle is found to be electrically active over a relatively narrow range of lengths close to the optimum length for tetanus of the whole muscle. The very shortest muscle lengths at which there is only minimal force development are not used in natural movements, while the declining limb of the length tension curve is at muscle lengths beyond the maximum in situ length.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051460406
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  • 79
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    Sensilla on the antennal flagellum of the sawyer beetles Monochamus notatus (Drury) and Monochamus scutellatus (Say) (Coleoptera: Cerambycidae) (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 513-531 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The antennae of the sawyer beetles Monochamus notatus and M. scutellatus were examined with the light and scanning electron microscopes to determine the types, number, distribution and innervation of the sense organs. Nine types of sensilla are described. Both short, thin-walled pegs (sensilla basiconica) and reversely curved thick-walled hairs (sensilla trichodea) are chemoreceptors. There are three types of long, thick-walled hairs (sensilla chaetica) which may be mechanoreceptors. One of these is modified in males to form unique snail-shaped pegs. A few dome-shaped organs, probably campaniform sensilla, were found.In addition to sense organs, many glands occur in association with the sensilla, and the antennae are well supplied with dermal glands connected by canals to small pores on the surface.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/jmor.1051460407
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  • 80
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470101
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  • 81
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    Epidermal downgrowths in regenerating rabbit ear holes (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 146 (1975), S. 533-542 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Rabbits are unique among mammals in that their ears can regenerate tissues from the margins of full thickness holes which grow in and completely fill the opening in about two months. The circular blastema that forms around the edges of the hole differentiates a new sheet of cartilage as it regenerates in a centripetal direction. Similar holes in other mammals fail to regenerate and form scar tissue instead of a blastema. Histological studies of the healing around the edges of rabbit ear holes reveal that during the second week, when the epidermis is completing its migration across the wound from the opposite sides of the ear, conspicuous tongues of epidermal cells grow down into the underlying tissues at the edges of the wound. These epidermal downgrowths are situated between the original intact dermis of the skin and the more central tissues which give rise to the blastema. Such downgrowths are of a transient nature, and are no longer found once the blastema rounds up toward the end of the second week. Since they are not found in the healing of similar wounds in rabbit ears prevented from regenerating by prior removal of their cartilaginous sheets, nor in the naturally nonregenerating ears of sheep and dogs, it is considered that these downgrowths of healing epidermis may play a role in the unusual regenerative response of ear tissues in the rabbit.
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    URL: http://dx.doi.org/10.1002/jmor.1051460408
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    The hyoid, laryngeal and pharyngeal regions of bathyergid and other selected rodents (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 229-250 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the hyoid, laryngeal and pharyngeal regions of the following rodent genera was studied: Cryptomys, Bathyergus, Georychus, Heliophobius, Heterocephalus, Ctenomys, Petromus, Thryonomys, Geomys, Cannomys, and Tachyoryctes. A number of morphological conditions unique to bathyergids, and associated with the use of the head and lower incisors in burrowing are described. The conditions include the formation of functional complexes of MM. sterno-geniohyoideus and omo-mylohyoideus, the presence of a unique deep oblique part of M. transversus mandibulae and a strong separate slip of M. platysma myoides pars mentalis. The hyoid skeleton is modified to allow the muscle complexes to act independently of the basihyal bone, and to allow the unusually protrusible tongue to be withdrawn. The nerves of the jugular foramen do not form a true pharyngeal plexus, and their configuration is influenced by the absence of a well developed internal carotid artery in hystricognaths. The morphology of the regions studied indicates a natural grouping of bathyergids, but one in which Heterocephalus is somewhat separate from the remaining bathyergid genera. The grouping of bathyergids and New and Old World hystricognath rodents into a suborder Hystricognatha is supported.
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    URL: http://dx.doi.org/10.1002/jmor.1051470208
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    Chelonian mental glands (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 275-291 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A survey of 69 of the 74 currently recognized chelonian genera revealed that 21 genera in three families (Emydidae, Platysternidae and Testudinidae) possess paired integumentary glands or gland vestiges in the anterior throat skin. These glands are here termed mental glands; they are holocrine and may be classified morphologically as follows: Class I mental glands are large, complex, multilobed, have specialized ducts, and are found only in the genus Gopherus: Class II mental glands are small, simple sacklike invaginations containing secretory cells or keratinizing cells. The structure of Class II glands varies from distinctive and saccular to shallow keratinized invaginations having no glandular tissue; they are found only in the families Platysternidae and Emydidae.Mental glands occur in 17 of the 22 genera in the subfamily Batagurinae (sensu McDowell, 64); only 2 of 9 genera in the subfamily Emydinae have these glands. The taxonomic occurrence of mental glands suggests that they are primitive structures. The loss of mental glands in most emydines is interpreted as a subfamilial trend toward integumentary simplification.
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    URL: http://dx.doi.org/10.1002/jmor.1051470303
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    Scanning electron microscopy of the air bladder in the spotted gar, Lepisosteus occulatus (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 293-298 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The surface of the gar respiratory epithelium was examined by scanning electron microscopy. Nonciliated and ciliated cells constitute the epithelium. Puffs appear to be an unusual feature of the ciliated cells as well as nonciliated cells. There appears to be a transition from nonciliated to puff ciliated cells through a puff stage. The role of the cell types as related to oxygen available in the air bladder is discussed.
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    The formation and cytochemical characterization of cortical granules in ovarian oocytes of the golden hamster (Mesocricetus auratus)This investigation was supported by grants (HD06822 to E.A.; Training Grant 5T01 6M 00406; Center Grant HD06645) from the National Institutes of Health, the United States Public Health Service. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 251-274 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The formation and cytochemical characterization of cortical granules in the ovarian oocytes of the golden hamster have been investigated by use of light and electron microscopical techniques. Particular emphasis is given to the changing population of organelles associated with cortical granule formation. Our observations indicate that cortical granules are produced by the participation of both the Golgi complex and the rough endoplasmic reticulum. Ultrastructural cytochemistry reveals that the cortical granules are composed of glycoprotein. The cortical granules are released at fertilization by a merocrine-type of secretory process.
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    Techniques for estimating allometric equations (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 299-307 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Morphologists have long been aware that differential size relationships of variables can be of great value when studying shape. Allometric patterns have been the basis of many interpretations of adaptations, biomechanisms, and taxonomies. It is of importance that the parameters of the allometric equation be as accurate estimates as possible since they are so commonly used in such interpretations.Since the error term may come into the allometric relation either exponentially or additively, there are at least two methods of estimating the parameters of the allometric equation. That most commonly used assumes exponentiality of the error term, and operates by forming a linear function by a logarithmic transformation and then solving by the method of ordinary least squares. On the other hand, if the error term comes into the equation in an additive way, a nonlinear method may be used, searching the parameter space for those parameters which minimize the sum of squared residuals. Study of data on body weight and metabolism in birds explores the issues involved in discriminating between the two models by working through a specific example and shows that these two methods of estimation can yield highly different results. Not only minimizing the sum of squared residuals, but also the distribution and randomness of the residuals must be considered in determining which model more precisely estimates the parameters.In general there is no a priori way to tell which model will be best. Given the importance often attached to the parameter estimates, it may be well worth considerable effort to find which method of solution is appropriate for a given set of data.
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    Masthead (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470401
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    A simplified placenta-like system for the transport of extraembryonic nutrients during embryogenesis of Bugula neritina (bryozoa)Contribution No. 17 from the Santa Catalina Marine Biological Laboratory. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 355-377 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Embryos of the marine cheilo-ctenostome bryozoan Bugula neritina undergo a marked increase in volume (about 500-fold) during embryogenesis while being retained in a brood chamber. Previous morphological studies indicate that shortly after transfer of the zygote to the brood chamber, the epithelium of the maternally-derived portion of the brood chamber, the ooecial vesicle, differentiates in regions adjacent to the embryonary space from a squamous to a columnar form suggesting that the parent is involved as a source of extraembryonic nutrients required for the extensive growth of the embryo.Results of the present ultrastructural study indicate that hypertrophy of the epithelial cells occurs only in that region of the ooecial vesicle which opposes the embryo, that differentiation (and subsequent regression) of the lining are predictable events correlated with the onset (and termination) of embryonic growth, and that hypertrophied cells are well equipped for the synthesis and transport of macromolecular materials across the vesicle wall to the developing embryo. Further, that portion of the embryo's ectoderm (the presumptive metasomal sac) in contact with this hypertrophied epithelium is morphologically specialized for the uptake of nutrients. Finally, shortly before release of the larva, this intimate association of the metasomal sac tissue and the hypertrophied ooecial vesicle lining epithelium is terminated by invagination of the sac and atrophy of the lining.
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    A gross and microscopic study of the respiratory anatomy of the antarctic weddell seal, Leptonychotes weddelli (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 309-335 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four species of Phocidae, or true seals, inhabit the waters surrounding the Antarctic continent. These animals are thought to have different diving capabilities. The Weddell seal, Leptonychotes weddelli, is known to be capable of attaining depths up to 600 meters.The respiratory system of the Weddell seal shows the usual adaptations to an aquatic environment characteristic of other marine mammals. These include lungs that undergo compression collapse at depths greater than 70 meters; hyaline cartilage in the tracheo-bronchial tree as far as the terminal bronchioles; and large amounts of smooth muscle surrounding the distal-most bronchioles. The collapsible lungs provide a mechanism by which air is forced from the alveoli adjacent to the pulmonary capillary beds thereby preventing the absorption of nitrogen gas into the bloodstream. The presence of hyaline cartilage throughout most of the tracheo-bronchial tree increases the effective dead air space that accommodates most of the air forced from the collapsed lungs. The smooth muscle surrounding the respiratory bronchioles prevents their collapse while under the pressures of a deep dive. Collapse of the respiratory bronchioles not supported by cartilage would trap air in the lung alveoli during a dive.In addition, large-sac-like “diverticulae” are found in the submucosa throughout the tracheo-bronchial tree. These diverticulae, which open directly into the lumen of the tree, appear to be modified glands whose cells, in most cases, do not appear to be specialized for secretory function. They are most numerous in the more distal bronchi and terminal bronchioles where they are situated on both the luminal and adventitial sides of the hyaline cartilage supporting the walls of the air passages. Diverticulae are not found in the respiratory bronchioles or in the respiratory portion of the lungs.
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    An anatomical, histochemical, and autoradiographic study of the ever-growing molar dentition of Microtus with comments on the role of structure in growth and eruptionThe paper is a condensation of a thesis submitted in partial fulfillment of requirements for the degree of Master of Arts in Biology at Hofstra University.Reported in part at the annual meetings of the American Society of Mammalogists, Tampa, Florida, 1972 and Binghamton, New York, 1974. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 337-353 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An analysis of the microanatomy of the molar dentition of Microtus utilizing histological, histochemical and autoradiographic techniques reveals a complex architecture with distinctive morphogenic mechanisms which respond to the functional requirements of the organism. These mechanisms include; the maintenance of continued growth and eruption of the molars to compensate for continued hard tissue loss from wear at the occlusal surface of the crown throughout the entire lifespan of the organism and a positive feedback repair mechanism to protect the growth systems from the potential destruction this normal occlusal wear could initiate. An awareness and understanding of these phenomena is of significant value for interpreting palentological specimens and formulating a theoretical model for interpreting the evolution of Microtine molar dentitions.
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    URL: http://dx.doi.org/10.1002/jmor.1051470307
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  • 91
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    Assay of cyclic 3′-5′-monophosphate in the regenerating forelimb of the newt, TriturusSupported by grants from American Cancer Society, the National Institutes of Health, and the Multiple Sclerosis Society. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 379-383 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cyclic adenosine 3′-5′-monophosphate content of four regenerate stages in the forelimb of the newt, Triturus viridescens, was assayed using the Gilman method and compared to the content in the normal, unamputated, forelimb. The concentration was found to be highest in the earliest stages of regeneration, followed by a sharp drop and then a rise to a plateau approximately that of the unamputated limb. The possibility that cyclic AMP acts as a second messenger for nervous and hormonal influences on regeneration is discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470402
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  • 92
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    A study of the fine structure of the accessory muscle of the horseshoe crab, Tachypleus gigas (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 147 (1975), S. 439-457 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The accessory muscle of the walking leg of the horseshoe crab, Tachypleus gigas, was examined electron microscopically. The muscle fibers vary in size but are small in diameter, when compared with other arthropod skeletal muscles. They are striated with A, I, Z and poorly defined H bands. The sarcomere length ranges from 3-10 μm with most sarcomeres in the range of about 6 μm. The myofilaments are arranged in lamellae in larger fibers and less well organized in the smaller ones. Each thick filament is surrounded by 9-12 thin filaments which overlap. The SR is sparse but well organized to form a fenestrated collar around the fibrils. Individual SR tubules are also seen among the myofibrils. Long transverse tubules extend inward from the sarcolemma to form dyads or triads with the SR at the A-I junction. Both dyads and triads coexist in a single muscle fiber, a feature believed to have evolutionary significance. The neuromuscular relationship is unique. In the region of synaptic contact, the sarcolemma is usually elevated to form a large club-shaped structure containing no myofilaments and few other organelles. The axons or axon terminals and glial elements penetrate deep into the club-shaped sarcoplasm and form synapses with the fiber. As many as 13 terminals have been observed within a single section. Synaptic vesicles of two types are found in the axon terminals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051470405
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  • 93
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    Ultrastructural characterization by ruthenium red of the surface of the fat globule membrane of human and rat milk with data on carbohydrates of fractions of rat milk (1975)
    Springer
    Cell & tissue research 157 (1975), S. 17-24 
    Details
    ISSN: 1432-0878
    Keywords: Milk ; Fat globule membrane ; Carbohydrates ; Chemistry ; Ruthenium red ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat globules of the cream fractions of human and rat milk were stained with ruthenium red. Under the electron microscope, discrete granules and an amorphous coat of lesser density are seen at the surface of the milk fat globules. Since ruthenium red binds anionic groups selectively, it is probable that the granules containe the greatest concentration of these groups. The cream fraction of rat milk contains hexoses, hexosamines, methylpentoses and sialic acid. Methylpentoses and hexosamines are significantly enriched in the cream fraction. It is concluded that the finding of a surface coat in milk fat globules is in keeping with the Bargmann-Knoop model and suggests a distinct mechanism for carrying certain complex carbohydrates in milk. The role of the negative charges at the outer surface of the membrane coat in maintaining fat globules in suspension and in binding certain cations such as calcium is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223228
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  • 94
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    Structure and innervation of the pineal gland of the rabbit, Oryctolagus cuniculus (L.) (1975)
    Springer
    Cell & tissue research 157 (1975), S. 25-51 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland (Rabbit) ; Autonomic innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the rabbit pineal gland two types of postganglionic nerve endings were found which are characterized by the presence of small dense-core vesicles or small clear vesicles. Pharmacological and cytochemical experiments showed them to be noradrenergic and cholinergic, respectively. Both types were often present in the same nerve bundle, occasionally in close apposition. Intrapineal neurons were only rarely observed. They showed cholinergic synapses on their perikaryon and dendrites as well as noradrenergic axo-dendritic close eontacts. Bilateral extirpation of the superior cervical ganglia revealed the postganglionic sympathetic origin of the pineal noradrenergic nerve fibres. Moreover, it appeared that these ganglia are hardly, if at all, involved in the pathway of pineal cholinergic innervation. The results obtained from lesions of both facial nerves, taken together with the results reported in the literature, led to the conclusion that the postganglionic cholinergic nerve fibres in the pineal are of parasympathetic origin. A model for the sympathetic and parasympathetic pineal innervation is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223229
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  • 95
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    The fine structure and phosphatase cytochemistry of the Golgi complex and associated structures in the Sertoli cells of Syrian hamsters (1975)
    Springer
    Cell & tissue research 157 (1975), S. 227-238 
    Details
    ISSN: 1432-0878
    Keywords: Golgi complex ; GERL ; Sertoli cell ; Ultrastructure ; Phosphatase cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Golgi complex in the Sertoli cell of the Syrian hamster is well developed and consists of stacks of cisternae and associated vesicles. The inner-and outermost cisternae of the Golgi stacks are usually moderately dilated and exhibit numerous fenestrations. The middle portions of the intermediate cisternae are greatly flattened and not fenestrated, but toward the periphery these cisternae gradually become dilated and show a few fenestrations. On the inner aspect of the Golgi stacks the following structures are seen frequently: (1) one or two series of linearly arrayed circular profiles some of which are interconnected by tubules; (2) networks of anastomosing tubules with circular or oval meshes (800 to 1200 Å in diameter); and/or (3) irregularly disposed tubules. The circular profiles and tubules are approximately 450 Å in diameter. Acid phosphatase activity was localized in these anastomosing tubules when the tissues were incubated for more than one hour in a modified Gomori's medium (Barka and Anderson, 1963). Strong thiamine pyrophosphatase activity was demonstrated in the inner one to three cisternae of the Golgi stacks but not in the associated tubules. The system of the Golgi associated tubules is morphologically and histochemioally distinct from the Golgi stacks and is probably equivalent to the Golgi-endoplasmic reticulum-lysosome system (GERL) in other cell types. The three dimensional aspects of the GERL-equivalent system are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222068
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  • 96
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    Studies on the fine structure of the cuticle of Porcellidium, crustacea Copepoda (1975)
    Springer
    Cell & tissue research 159 (1975), S. 399-412 
    Details
    ISSN: 1432-0878
    Keywords: Porcellidium (copepode) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Deux espèces de Porcellidium ont été examinées en microscopic à balayage et sur coupe avec les techniques habituelles (P. viride provenant de Banyuls-sur-mer, Méditerranée et P. fimbriatum de Roscoff, Manche; ces deux espèces vivent sur les Algues vertes du genre Ulva). Nous avons retrouvé les ultrastructures classiques de la cuticule, observées dans les principaux groupes de Copépodes. Quatre caractères nouveaux distinguent la cuticule dorsale des Porcellidium: 1. Différenciation d'un système de microvillosités externes, avec un niveau dense aux électrons, très contrasté par rapport aux extrémités d'où semblent partir de fins filaments englobant une population assez dense de Bactéries. 2. Cette plage de microvillosités recouvre un relief assez particulier de la procuticule, évoquant par ses cratères un paysage lunaire. 3. Présence de canaux cytoplasmiques ramifiés et terminés par une expansion arrondie, sous l'épicuticule. 4. Existence d'un système de vésicules reliant la base des microvillosités aux extrémités renflées des canaux cytoplasmiques. L'association des Bactéries est régulière et une grande proportion de celles-ci est en cours de cytolyse. La système de microvillosités et de canaux ne nous parait pas étranger à la présence de cette population bactérienne.
    Notes: Summary Two species of Porcellidium have been studied by scanning and transmission electron microscopy: P. viride from Banyuls-sur-mer, Mediterranian Sea and P. fimbriatum from Roscoff, English Channel. Both species live on green Algae of the genus Ulva. We confirmed previous descriptions of the cuticular ultrastructure in the main groups of Copepods. Four new characteristics however were shown to occur in the backcuticle of Porcellidium: 1. The presence of a system of highly differentiated external microvilli showing electron dense basal portions and less electron dense tips, from which thin filaments project towards a large population of Bacteria associated with the Copepod. 2. The surface of the cuticle resembles a lunar landscape with craters. The sheet of microvilli closely follows the contour of the cuticle. 3. The presence of branched cytoplasmic canals with swollen extremities (beneath the epicuticle) extending from the epidermal cells. 4. Systems of vesicles lying between the bases of the microvilli and the expansions (ampullae) at the tip of the cytoplasmic canals. The association of Bacteria with the cuticle is constant and many of these are apparently undergoing cytolysis. The system of microvilli and of cytoplasmic canals are apparently related to the presence of the bacterial microflora.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221786
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  • 97
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    Ultrastructure of the Budgerigar testis during a photoperiodically induced cycle (1975)
    Springer
    Cell & tissue research 159 (1975), S. 541-550 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Budgerigar ; Photoperiod ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Spermatogenesis in the Budgerigar can be arrested by reducing the birds' photoperiod to 8 hours of daylight or less. When this occurs, Sertoli cell cytoplasm shows a great increase in the size and number of residual bodies, while the smooth endoplasmic reticulum is reduced. If the bird is kept at 8 hours of daylight for some weeks large lipid droplets are seen in Sertoli cytoplasm, and degenerated spermatids are apparently phagocytosed. The interstitium shows fewer active Leydig cells, a paucity of lipids and occasional ovoid mitochondria. The basal lamellae of the tubule which are thick and convoluted before and during spermatogenesis become thinner and straighter. It is thought that these morphological changes reflect changes in metabolic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221709
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  • 98
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    Morphology of the perivascular regions of the rat neural lobe in relation to hormone release (1975)
    Springer
    Cell & tissue research 159 (1975), S. 551-561 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis, rat ; Exocytosis ; Blood vessels ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to dehydration by drinking 2% saline for four days were examined electron microscopically and compared to untreated controls. The ultrastructure of the blood vessels and the tissues surrounding them were examined and it was found that, although few exocytotic figures could be seen in either group of animals, a significantly larger (P〈0.01) number of small vesicles were found in nerve endings adjacent to the perivascular space in the saline treated group when compared to nerve endings not closely associated with blood vessels. No differences were found in the control group of animals, which supports the suggestion that the vesicles could arise from a membrane recapture process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221710
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  • 99
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    The labrum of Schedorhinotermes minor soldier (Isoptera, Rhinotermitidae) (1975)
    Springer
    Cell & tissue research 160 (1975), S. 81-98 
    Details
    ISSN: 1432-0878
    Keywords: Sensillae ; Isoptera ; Schedorhinotermes ; Labrum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'étude du labre du petit soldat de Schedorhinotermes, en microscopie photonique et électronique (balayage et transmission), a permis de préciser la distribution, les types et la structure des organes sensoriels présents sur celui-ci. Trois types de sensilles ont été observés: de nombreux sensilles campaniformes situés dans les régions antéro-latérales et deux types de sensilles trichoïdes: de petites soies (5 μ de longueur) réparties sur toute la surface du labre et quelques grandes soies (50 à 100 μ de longueur) localisées sur le bord antérieur du labre. Ces deux types de soies assurent à la fois une fonction mécanoréceptrice et chimioréceptrice. De nombreux orifices de glandes épidermiques débouchent également sur le labre qui porte à son apex une brosse formée de nombreuses écailles cuticulaires aplaties et non innervées. Une interprétation fonctionnelle est avancée, elle est basée sur les résultats ultrastructuraux obtenus et sur ce que l'on connait du comportement défensif du soldat.
    Notes: Summary The labrum of Schedorhinotermes minor soldier was examined to determine the distribution, types and structures of sense organs present with both light microscopy and scanning and transmission electron microscopy. Three types of sensilla were recognized: campaniform sensillae and two types of sensilla trichodea, the short bristles and the long bristles. The campaniform sensillae are singly-innervated receptors distributed in large numbers on the anterolateral margins of the labrum. The short and long bristles are multiinnervated; the former are found all over the surface, the latter are much more scarce and are found only at the front of the labrum. Both are at the same time chemo-and mechanoreceptors. The labrum is strewn with many glandular pits and exhibits at its apex a brush of cuticular not innervated spines. On the basis of ultrastructural evidence and of what we know of the defence mechanisms of the soldier, a functional interpretation is attempted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219843
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  • 100
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    Structure and histochemistry of the normal intestine of the fowl (1975)
    Springer
    Cell & tissue research 160 (1975), S. 125-138 
    Details
    ISSN: 1432-0878
    Keywords: Avian intestine ; Duodenum ; Ultrastructure ; Crypt cells ; Paneth cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the development and maturation of intestinal chief cells from the duodenal crypts of the fowl has been described in detail. Three areas within the crypt can be recognised: (1) the crypt base where cell division is frequent but cell development is minimal; (2) the mid-crypt region where rapid growth and development of the cells takes place; and (3) the zone of differentiation where final development and functional maturation occurs. The structure of the fowl's intestinal crypt is very similar to that described for the mammal. The results are discussed in relation to previous histochemical studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219846
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