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  • 1930-1934  (5)
  • Life and Medical Sciences  (5)
Material
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 52 (1931), S. 525-533 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: There are twenty-seven spermatogonial chromosomes in Tenoder'a sinensis, three of which are larger than the others and lag behind in anaphase. These three chromosomes have been traced through the prophases of the first spermatocyte to the metaphase, where they appear as a hexad. In the first spermatocyte division two of the constituent diads of the hexad pass to one pole, the remaining one to the other, thus giving rise to two types of second spermatocytes, one with thirteen and the other with fourteen chromosomes. There are twenty-eight chromosomes in somatic metaphases of the female; four of these chromosomes are larger than the others. The sex chromosomes of the male are represented by the formula Xa + Y + Xb, that of the female by 2Xa + 2Xb.Similar conditions are reported for Mantis religiosa and Stagmomantis carolina.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Golgi bodies of the nerve cells of the grasshopper are discrete elements composed of an osmiophilic cortex and an osmiophobic medulla. When seen in face, they appear ring-like, semicircular, or crescentic. The osmiophilic portion is interpreted as the homologue of the classical Golgi apparatus and may under certain conditions be dissolved away, leaving clear spaces homologous to the canalicular apparatus (negative image of Golgi apparatus). When the osmiophilic portion is dissolved, the osmiophobic portion remains as a definite structure which apparently has no homologue in the classical Golgi apparatus. The mitochondria are granular, rod-like, or filamentous and show no transformation into Golgi bodies. Neutral-red bodies (‘vacuome’) of two kinds have been observed, neither of which is a constant preformed structure or has any relationship to the Golgi bodies. Prolongations of the capsule (trophospongium?) of the nerve cell penetrate into the cell approximately one-third the distance to the nucleus. These are interpreted as supportive rather than nutritive in function. A basket-like net of neurofibrillae surrounds the nucleus. It is suggested that the networks described as Golgi apparatus in certain invertebrate nerve cells may really consist of these neurofibrillae.The conclusion of Parat that Golgi material consists either of mitochondria or ‘vacuome’ is rejected. The idea that all structures in the living cell which stain with neutral red (‘vacuome’) are homologous is also rejected.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The parietal cells of the salivary glands of the grasshopper are large and roughly spherical or sometimes pyramidal in form, scattered for the most part singly among the zymogenic cells of the lobules. They possess a magnificent system of intracellular canaliculi into which their secretions are directly emptied and conveyed to the exterior of the cell. These intracellular canaliculi are strikingly impregnated with osmic-acid methods (Nassonov, Mann-Kopsch) in a manner comparable to the contractile vacuole of Paramecium as described by Nassonov. However, in addition to the impregnated system of intracellular canaliculi, Golgi bodies are found evenly distributed throughout the cell in the form of crescents, semicircles, or ring-like structures typical of insect tissue.Inasmuch as a direct homology between the intracellular canaliculi and the contractile vacuole of Paramecium, both from the point of view of morphology and physiology, seems justified, we question the inference drawn by Nassonov that the impregnated walls of the contractile vacuole in Paramecium actually represent Golgi material. Deduction is made from these and previous studies that the magnificent network of ‘vacuome-Golgi apparatus’ described by Parat and Painlevé ('24) in the salivary glands of Chironomus larvae is nothing more or less than intracellular secretory canaliculi.Mitochondria in the parietal cells are abundant in the characteristic form of short rods and filaments. No evidence of a direct transformation of mitochondria into Golgi bodies. as held by Parat, was observed. Golgi bodies and mitochondria show no marked topographical relationship to the intracellular secretory canaliculi.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 56 (1934), S. 593-601 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The rate of maturation and of development during the first 4 days has been followed in Melanoplus differentialis eggs (from mated females) collected (1) just before they were laid, or (2) immediately after oviposition had been completed and (1) either fixed at once, or (2) after incubation at 25°C. for definite periods.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 56 (1934), S. 603-619 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Maturation and early cleavage in unfertilized Melanoplus differentialis eggs have been followed with material secured immediately before as well as after oviposition, and (1) fixed at once, or (2) held in an incubator at 25°C. and, subsequently, fixed at selected intervals. Eggs ready to be laid were all found in the metaphase of the first maturation division. The second polar body is given off (at 25°C.) within 5 to 7 hours after laying. Meiosis appears to be unaffected by the absence of the sperm nucleus and proceeds at the same rate as in fertilized eggs. No morphological differences could be found between the process here and in eggs from mated females.During early cleavage, or later, the diploid number of chromosomes may be restored in some (or perhaps all) cells of the embryo.Development begins in the greater number of these unfertilized eggs but is successfully completed in only a very few.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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