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Notes: The sperm of the shiner surfperch are packaged into high density aggregations which are introduced into the female genital tract at insemination. Germ cell differentiation occurs within cysts formed by nongerminal Sertoli cells. In late spermiogenesis, spermatozoa within the cysts come to lie parallel to each other and become more densely packed. These sperm packets (spermatophores), containing approximately 600 spermatozoa, then are released into the efferent sperm ducts.The exact nature of the spermatophore binding material is not known, but a major component is proteinaceous and is synthesized in the rough endoplasmic reticulum of the efferent sperm duct epithelial cells. The mechanism by which the spermatophores pass from cysts into ducts is not clear. It appears that whereas many Sertoli cells degenerate causing the cyst wall to break down, many Sertoli cells do not degenerate, but rather assume the configuration of columnar duct cells. The spermatophores remain intact within the testicular ducts, but rapidly dissolve within the female ducts in response to increased pH.

Notes: The telemetered electromyographic activity (EMG) of select hindlimb muscles of unrestrained cats during standing, walking, trotting, and galloping have been recorded. Simultaneous cinematographic records permitted close correlation of muscle activity and locomotor behavior. In general, the pattern of extensor activity of the ankle, knee, and hip during locomotion is fairly consistent, while that of the flexors is more variable.Changes in basic EMG patterns from walk, to trot, to gallop are most evident in the two-jointed muscles associated with the knee and hip. Progressively greater variation of activity onset and cessation can be seen among extensor muscle groups from the walk, to trot, to gallop. Co-activation of the joint extensors and flexors, especially of the hip, at the end of the stance phase (E3) is slight in the walk, moderate in the trot, and considerable in the gallop. These EMG changes are necessary to meet the demands imposed upon the musculature at the faster gaits, particularly galloping, which include limb rigidity as related to loading, momentum as related to the limb's directional change from the stance phase to the swing phase, and lower spinal movements.The peroneal muscles of the ankle and the gluteal muscles of the hip show extensor activity and act as joint stabilizers during locomotion. Both biceps femoris anterior muscle and biceps femoris posterior muscle show consistent hip extensor patterns at all gaits. During quiet standing, extensor activity about the knee, ankle, and metatarsophalangeal joints is evident; but the hip extensor and flexor musculature is remarkably silent.EMG data for unrestrained cats are compared to those of dogs on a treadmill (Tokuriki, '73a,b, '74; Wentink, '76) and those recorded from decerebrate cats (mesencephalic preparation) during controlled locomotion (Gambaryan et al., '71). The EMG patterns from decerebrate cats are more consistent at the walk and gallop within functional groups of muscles at the ankle, knee, and hip than the EMG patterns observed in unrestrained cats or animals moving on a treadmill.

Notes: End-plate distributions have been determined for three frog muscles of different morphology in order to relate end-plate topography to spatial muscle structure and nerve branching. Koelle's cholinesterase technique was applied, both on whole muscles and frozen sections. The end-plates of the short parallel-fibered cutaneus pectoris muscle appeared to be located in short bands along the nerve branches. The nerve tree is restricted to a zonal area across the middle part of the muscle. Depending on the way the nerve branches, the end-plate bands form innervation patterns, varying from one single continuous band to multiple distributed bands. In the latter case one frequently observes that different end-plate bands do not run across the same longitudinal muscle fiber area, although the respective nerve branches run parallel across this area. The long parallel-fibered sartorius muscle has a wider nerve tree and exhibits the same phenomenon for close parallel nerve branches, but end-plate bands along parallel nerve branches far apart cover the same muscle fiber area. The end-plate distribution in the bipennate, short-fibered gastrocnemius is zonal throughout the muscle except in certain compartments containing tonic fibers. The end-plate zone centers around the inner aponeurosis about half-way between the muscle tendon junctions of the fibers and is visible only at the muscle surface where muscle fibers run over their entire length at that surface. The results are of general use in the electrophysiology of neuromuscular transmission because they illustrate how in certain twitch muscles neuromuscular morphology may help to localize end-plates.

Notes: When a larva of Haplothrips verbasci is ready to feed, it grasps the surface of the leaf with its pretarsi, sinks down between its front legs, lifts its head, and places the tip of its mouthcone against the surface. It then shortens its mouthcone and punches a hole in the epidermis by rapidly and repeatedly protracting and retracting its left mandibular stylet. The thrips then inserts its two maxillary stylets as a unit into the wound with a series of rapid thrusts and withdrawals, salivating continuously while doing so. When a food source in the epidermis or mesophyll is found, probing and salivation stop and cibarial pumping begins. Cytoplasm is sucked into the opening at the tip of the protracted stylets, up the food canal between them and into the cibarium.Probing and feeding can occur without mandibular intervention but uptake of liquid seems to require use of the mutually coadapted maxillary stylets, even when these are fully retracted.Prior to molting, the larva protracts its maxillary stylets maximally and, in the pharate state, seems incapable of feeding or drinking.Structures used in feeding are fully described and are shown to resemble those of Hemiptera except for the presence of maxillary and labial palpi and the absence of the loral lobes, right mandible and of a salivary canal between the protracted maxillary stylets. Seven single and 18 paired muscles function in the feeding act, nine less than in adults of the same species.Differences in the feeding mechanism of terebrantian and tubuliferous thrips are discussed and evidence is presented to suggest that the simplified and more highly specialized mouthparts of the latter insects are adaptations for feeding in confining spaces.

Notes: In contemporary entomology the morphological characters of insects are not always treated according to their phylogenetic rank. Fossil evidence often gives clues for different interpretations. All primitive Paleozoic pterygote nymphs are now known to have had articulated, freely movable wings reinforced by tubular veins. This suggests that the wings of early Pterygota were engaged in flapping movements, that the immobilized, fixed, veinless wing pads of Recent nymphs have resulted from a later adaptation affecting only juveniles, and that the paranotal theory of wing origin is not valid. The wings of Paleozoic nymphs were curved backwards in Paleoptera and were flexed backwards at will in Neoptera, in both to reduce resistance during forward movement. Therefore, the fixed oblique-backwards position of wing pads in all modern nymphs is secondary and is not homologous in Paleoptera and Neoptera. Primitive Paleozoic nymphs had articulated and movable prothoracic wings which became in some modern insects transformed into prothoracic lobes and shields. The nine pairs of abdominal gillplates of Paleozoic mayfly nymphs have a venation pattern, position, and development comparable to that in thoracic wings, to which they are serially homologous. Vestigial equivalents of wings and legs were present in the abdomen of all primitive Paleoptera and primitive Neoptera. The ontogenetic development of Paleozoic nymphs was confluent, with many nymphal and subimaginal instars, and the metamorphic instar was missing. The metamorphic instar originated by the merging together of several instars of old nymphs; it occurred in most orders only after the Paleozoic, separately and in parallel in all modern major lineages (at least twice in Paleoptera, in Ephemeroptera and Odonata; separately in hemipteroid, blattoid, orthopteroid, and plecopteroid lineages of exopterygote Neoptera; and once only in Endopterygota). Endopterygota evolved from ametabolous, not from hemimetabolous, exopterygote Neoptera.The full primitive wing venation consists of six symmetrical pairs of veins; in each pair, the first branch is always convex and the second always concave; therefore costa, subcosta, radius, media, cubitus, and anal are all primitively composed of two separate branches. Each pair arises from a single veinal base formed from a sclerotized blood sinus. In the most primitive wings the circulatory system was as follows: the costa did not encircle the wing, the axillary cord was missing, and the blood pulsed in and out of each of the six primary, convex-concave vein pair systems through the six basal blood sinuses. This type of circulation is found as an archaic feature in modern mayflies. Wing corrugation first appeared in preflight wings, and hence is considered primitive for early (paleopterous) Pterygota. Somewhat leveled corrugation of the central wing veins is primitive for Neoptera. Leveled corrugation in some modern Ephemeroptera, as well as accentuated corrugation in higher Neoptera, are both derived characters. The wing tracheation of Recent Ephemeroptera is not fully homologous to that of other insects and represents a more primitive, segmental stage of tracheal system.Morphology of an ancient articular region in Palaeodictyoptera shows that the primitive pterygote wing hinge in its simplest form was straight and composed of two separate but adjoining morphological units: the tergal, formed by the tegula and axillaries; and the alar, formed by six sclerotized blood sinuses, the basivenales. The tergal sclerites were derived from the tergum as follows: the lateral part of the tergum became incised into five lobes; the prealare, suralare, median lobe, postmedian lobe and posterior notal wing process. From the tips of these lobes, five slanted tergal sclerites separated along the deep paranotal sulcus: the tegula, first axillary, second axillary, median sclerite, and third axillary. Primitively, all pteralia were arranged in two parallel series on both sides of the hinge. In Paleoptera, the series stayed more or less straight; in Neoptera, the series became V-shaped. Pteralia in Paleoptera and Neoptera have been homologized on the basis of the fossil record.A differential diagnosis between Paleoptera and Neoptera is given. Fossil evidence indicates that the major steps in evolution, which led to the origin first of Pterygota, then of Neoptera and Endopterygota, were triggered by the origin and the diversification of flight apparatus. It is believed here that all above mentioned major events in pterygote evolution occurred first in the immature stages.

Notes: Oocytes and nurse tissue of Bruchidius differentiate from germ cells during the extended period of pupal development (7.2 ± 0.6 days). A system of 15 pupal stages correlates ovarian development with changes in pigmentation of the eyes, maxillae, alae and tarsalia. The ovarioles grow in length at a constant rate, though their width does not change.A differentiating zone, consisting of germ cells and the basal layer of interstitial cells, arises at the base of the tropharium and separates presumptive oocytes and nurse cells. Early in pupal development the germ cells are arranged in primary syncytia with the cells connected by persisting intercellular bridges filled with fusomal material, never with larger particles, such as mitochondria. At later stages membrane disintegration changes the primary syncytium into a secondary one including all nurse cell nuclei.Nutritive cords are first noticeable when differentiation of oocytes and nurse cells starts. The cords seem to be of primary origin, i.e., they are connections between sister cells which become elongated as these cells are separated during growth. This is indicated by the persistence of intercellular bridges which are sometimes found as part of the membrane of growing nutritive cords connecting young oocytes with the nurse cell syncytium.

Notes: The formation of protein-carbohydrate yolk in the statoblast of a fresh-water bryozoan, Pectinatella gelatinosa, was studied by electron microscopy. Two types (I and II) of yolk cells were distinguished. The type I yolk cells are mononucleate and comprise a large majority of the yolk cells. The type II yolk cells are small in number; they become multinucleate by fusion of cells at an early stage of vitellogenesis. In both types of yolk cells, electron-dense granules (dense bodies) are formed in Golgi or condensing vacuoles, which are then called yolk granules. For the formation of yolk granules, the following processes are considered: 1. Yolk protein is synthesized in the rough-surfaced endoplasmic reticulum (RER) of the yolk cells. 2. The synthesized protein condenses in the cisternal space of the RER and is packaged into small oval swellings, which are then released from the RER as small vesicles (Golgi vesicles, 300-600 A in diameter). 3. The small vesicles fuse with one another to form condensing vacuoles, or with pre-existing growing yolk granules. 4. In the matrix of the condensing vacuoles or growing yolk granules, electron-dense fibers are fabricated and then arranged in a paracrystalline pattern to form the dense body. 5. After the dense body reaches its full size, excess membrane is removed and eventually the yolk granules come to mature. Toward the end of vitellogenesis of the yolk cells, the cytoplasmic organelles are ingested by autophagosomes derived from multivesicular bodies and disappear.

Notes: Testis structure in four species of goodeid teleosts is described. Testicular tubules terminate blindly at the testis periphery where spermatogonia are located. In goodeid teleosts, development of sperm takes place synchronously within cysts whose periphery is made up of a single layer of Sertoli cells. Upon completion of spermiogenesis, spermiation ensues wherein sperm are shed, as spermatozeugmata, into the testis efferent duct system. Subsequently, Sertoli cells, which comprised the cyst periphery, transform into efferent duct cells.Sertoli cells phagocytize residual bodies and are involved in the formation of spermatozeugmata. The structure of the goodeid spermatozeugmatum is quite different from that observed in the related poeciliids. It is concluded, in view of this and other considerations, that the goodeids and poeciliids have independently evolved solutions to the problems of internal fertilization and gestation.

Notes: The papillae basilares of 12 species of lizards from seven different families were studied by SEM. The iguanids, Sceloporus magister and S. occidentalis, have typical “iguanid type” papillae with central short-ciliated unidirectional hair cell segments and apical and basal long-ciliated bidirectional hair cell segments. These species of Sceloporus are unique among iguanids in that the bidirectional segments consist of but two rows of hair cells. The agamids, Agama agama and Calotes nigrolabius, have an “agamid-anguid type” papilla consisting of an apical short-ciliated unidirectional hair cell segment and a longer basal bidirectional segment. Agama agama is unusual in having a few long-ciliated hair cells at the apical end of the apical short-ciliated segment. The agamid, Uromastix sp., has an “iguanid type” papilla with a central short-ciliated unidirectional segment and apical and basal bidirectional segments. The anguid, Ophisaurus ventralis, has an “iguanid” papillar pattern with the short-ciliated segment centrally located. All the short-ciliated hair cells of the above species are covered by a limbus-attached tectorial network or cap and the long-ciliated hair cells, only by loose tectorial strands.The lacertids, Lacerta viridis and L. galloti, have papillae divided into two separate segments. The shorter apical segment consists of opposingly oriented, widely separated short-ciliated cells covered by a heavy tectorial membrane. The apical portion of the longer basal segment consists of unidirectionally oriented hair cells, while the greater part of the segment has opposingly oriented hair cells.The xantusiids, Xantusia vigilis and X. henshawi, have papillae made up of separate small apical segments and elongated basal segments. The apical hair cells are largely, but not exclusively, unidirectional and are covered by a heavy tectorial cap. The basal strip is bidirectional and the hair cells are covered by sallets. The kinocilial heads are arrowhead-shaped.The papilla of the cordylid, Cordylus jonesii, is very similar to that of Xantusia except that the apical segment is not completely separated from the basal strip.The papilla of the Varanus bengalensis is divided into a shorter apical and a longer basal segment. The hair cells of the entire apical and the basal three quarters of the basal segment are opposingly oriented, not with reference to the midpapillary axis but randomly to either the neural or abneural direction. The apical quarter of the basal segment contains unidirectional, abneurally oriented hair cells. The entire papilla is covered by a dense tectorial membrane.The functional correlations of the above structural variables are discussed.

Notes: The circulatory systems of four polystyelids, Botryllus schlosseri, B. primigenus, Botrylloides violaceus and Symplegma reptans, were compared. The palleal buds are connected to the parent zooid by a peduncle and to the colonial vascular system by connecting vessels. The peduncle of S. reptans disappears at an earlier stage of bud development than in B. primigenus; it survives the dissolution of the parent zooid in B. schlosseri and B. violaceus. The connecting vessel is formed by anastomosis between an epidermal outgrowth from the bud and a neighboring colonial vessel, and is characterized by the presence of a sphincter. The number of connecting vessels formed in a palleal bud is three in S. reptans, two in B. primigenus and one each in B. schlosseri and B. violaceus. In each species, the larva has eight rudiments of ampullae. In B. primigenus, the original ampullae degenerate soon after metamorphosis and new ampullae extend from the ventral epidermis of the oozooid. In the other species, the colonial vascular system is derived from the original ampullae.The whole colonial vascular system contracts and expands periodically, with regionally different phases. During each expansion cycle, the sphincter contracts once in B. primigenus and twice in S. reptans. The correlation may be due to blood pressure and the propagation of excitation through the colonial vascular system.

Notes: The mammalian ovary has been studied by optical microscopy and by scanning and transmission electron microscopy with the purpose of presenting an integrated view of the differentiating mammalian follicle. During follicular development, changes in the granulosa cells are particularly noteworthy and include dramatic modifications in cell shape coincident with antrum formation. The cytoplasmic processes of those granulosa cells immediately surrounding the oocyte, as well as the more peripheral granulosa cells comprising a second and third layer, traverse the zona pellucida, infrequently interdigitate with the microvilli of the egg, and make both desmosomal and gap junction contacts with the oocyte. The zona pellucida is thus distinguished by numerous fenestrations of varying diameters. The membrana limitans (basal lamina) is a bipartite structure composed of (a) a homogeneous stratum upon which the peripheral layer of granulosa cells rests, and (b) an outer region of collagen-like fibers. The specific advantages and limitations of the different methodologies utilized to study folliculo-genesis are discussed.

Notes: Papillary projections along the anterolateral margin of the tongue were observed in fetal and young stages of the striped dolphin, Stenella coeruleoalba. Papillary projections appear in the prenatal period and attain maximum development in the early postnatal period. They almost disappear by weaning. Vestigial eminences remain at the corresponding region, but they completely disappear in the adult. The papillary projections observed differ markedly from the lingual papillae of the general mammalian tongue as they are temporary, localized at the anterolateral margin and large in size. The projections were also present in young individuals of some other dolphins. No taste buds could be seen on the projections in any of the stages of all specimens observed. Such projections may have important mechanical functions during suckling in these mammals.

Notes: The fiber composition of the distal accessory flexor muscle (DAFM) and the branching pattern of its excitor axon were compared in several species of crabs, in the lobster and the crayfish. The muscle is composed exclusively of long sarcomere (〉 6 μm) fibers and therefore of the slow type. In all the crab species, except one, there is a distal to proximal gradient of fibers with increasing sarcomere lengths; this gradient is reverse in lobsters and crayfish. A proximal to distal gradient of increasing fiber diameters occurs in the DAFM of all crab species but not in the lobster and crayfish, in which all the fibers are approximately equal in diameter. The single excitatory axon traverses the width of the DAFM and gives off primary branches on either side in the lobster and crayfish but on only one side in crabs. The hypothesis that the axonal branching pattern may govern the regional distribution of fibers with differing sarcomere lengths in proposed.

Notes: The ultrastructure of the pinealocyte in the woodchuck, Marmota monax, was studied during the four seasons of the year. Fall cells have a fairly uniform cytoplasmic density, organelles consistent with synthetic and/or secretory activity and rather extensive pericapillary and intercellular spaces. Many winter pinealocytes are nearly devoid of ribosomes and granular endoplasmic reticulum but contain lipid droplets associated with mitochondria. Pericapillary and intercellular spaces are minimal. Spring glands have the greatest variation in cytoplasmic density with intercellular and pericapillary spaces similar to that seen in fall glands. Cells containing electron dense cytoplasm have Golgi zone associated, secretory granules, free ribosomes, short sections of granular endoplasmic reticulum and dense bodies. Cells with a more electron lucent cytoplasm are similar to the most frequently observed summer pinealocytes which have numerous Golgi zones but few associated secretory granules. Microtubules are prominent in the cytoplasm of these cells, the plasma membranes are smooth and intercellular and pericapillary spaces are minimal. A yearly rhythm or cyclic activity of the pinealocyte is suggested.

Notes: The non-secretory ameloblasts present at the enamel-free surfaces of maxillary teeth in the frog Rana pipiens were examined by electron microscopy at different stages of tooth development. Their main fine structural features seem to reflect a transport function. During early tooth development, the non-secretory ameloblasts adjacent to odontoblasts and predentin exhibit extensive lateral surface specializations and numerous cytoplasmic vesicles. During late tooth development, the non-secretory ameloblasts adjacent to mineralizing dentin show numerous cellular junctions, well-developed intercellular channels with numerous interdigitating processes and labyrinthine configurations at their distal surfaces. An intact basal lamina is present between the non-secretory ameloblasts and the dentin surface until the dentin becomes fully mineralized. At this stage the adjacent cells no longer exhibit surface specializations.It is suggested that the non-secretory ameloblasts may participate in the mineralization of adjacent dentin at the enamel-free surfaces. This surface dentin becomes fully mineralized at a later stage of development than the underlying dentin.

Notes: The developmental morphology of regenerating male breast feathers of the jungle fowl was studied at the ultrastructural level. The process of keratinization was observed in the three types of cells which form feather barbs: barbule cells, cortical cells, and medulla cells. Keratinization first became evident in the barbule cells and resembled the process of keratinization as observed in hair cortical cells and embryonic down feathers. Eventually the whole cytoplasmic area of the barbule cell was occupied by keratin.The barb cortex cells became keratinized in a similar fashion as the barbule cells but not until they were developmentally twice as old as the barbule cells. When keratinization was complete in these cells, the keratin was in the form of large agglomerates scattered in the cytoplasm.The barb medulla cells showed no obvious signs of keratinization until they were developmentally three times as old as the barbule cells. Keratin filament bundles were first seen near the plasma membranes of the medulla cells. Large empty vacuoles appeared in the cytoplasm which also contained moderate amounts of glycogen.

Notes: The ultrastructure of neuromuscular junctions in the twitch fibers of the stapedius muscle of Gallus gallus (domesticus) was investigated as part of a series of neurophysiological studies. Among the morphological features observed were elongated end-plates with numerous large and clear synaptic vesicles mixed with larger dense core vesicles and irregular or aperiodic “active sites” in the presynaptic membrane where synaptic vesicles were focused. The most remarkable features of these junctions were large synaptic clefts (50-80 nm) and the absence of junctional folds in the sarcolemmal surface. Unlike the large periodic junctional folds seen in the neuromuscular junctions of frogs and in the fast twitch fibers of the mammalian stapedius, the preparations studied only show small aperiodic invaginations (primitive folds) in the postsynaptic membranes. This morphological feature remains essentially constant from newly hatched to adult chickens. While these smooth junctions are consistent with earlier findings of inconspicuous junctional folds in the twitch fibers of the chicken posterior latissimus dorsi they are unlike those seen in the fast twitch fibers of the mammalian stapedius muscle, or other twitch fibers in general. The morphological findings of the present study may also suggest that the simple, unmodified neuromuscular junctions in the stapedius of Gallus may be a useful preparation for studies of synaptic membrane structures that employ the freeze-fracture technique.

Notes: A skeletal neomorph - the preglossale - is described from the tip of the tongue in Passer. This medial unpaired skeletal element is a dorsally open trough articulating with the anterior tips of the paraglossalia and supporting the heavy epidermal pad of the seed-cup. The large paired Mm. hypoglossus anterior originate from the posterior half of the preglossale and insert onto the anterior bodies of the paired paraglossalia; they serve to depress the anterior portion of the preglossale. A regular pattern of dermal papillae is present in the seed-cup; these are arranged in about 20 rows of six to 8 papillae per row. Each papilla contains a series of Merkel cells and associated nerve endings (touch receptors). The seed-cup serves to orient and hold the seed in place while it is being husked; the battery of tactile receptors provides information on the position of the seed on the tongue. The preglossale serves to support the seed-cup and to change its shape - the curvature of the dorsal surface - as it is depressed relative to the paraglossalia. The paraglossale and associated features of the seed-cup in Passer would provide a valuable preparation to study a diversity of problems such as developmental interactions between endomesodermal and ecto-mesenchymal skeletal features, the ontogenetical development of Merkel cells, and the sensory physiology of Merkel cells and their associated nerve endings as tactile corpuscles.

Notes: The structure of the longitudinal zebra stripes on the thorax of adult Zaprionus vittiger has been investigated by light-, polarization-, transmission electron-, and scanning electron microscopy. Each stripe consists of a central white stripe of about 50 μm width and two lateral dark brown stripes about 30 μm wide. Three different types of trichomes occur: Very long bent trichomes of the grooved-type, long bent trichomes of the crested-type, and short straight trichomes. The central white stripe contains neither bristle organs nor short straight trichomes but carries many long bent trichomes most of which are of the grooved type, contain two cavities and polarize the light in the polarization microscope. The dark brown stripes carry bristle organs and many trichomes of the short and straight-type. Bent trichomes of the crested-type are found on the whole zebra stripe at about equal frequencies; they contain no cavities and do not polarize the light. The cuticle of the dark stripes is underlain by pigment cells. It is suggested that the pigment granules in the epidermal cells cause the dark color of the dark brown stripes, whereas the form and structure of the bent grooved type trichomes cause the white color of the central stripe.

Notes: New data on the brain of Latimeria indicate that previous estimates of the brain weight were too high by a factor of two. Our data suggest a brain weight of 1.1-1.5 grams for a specimen with a body weight of 30 kilograms. Quantitative data on major divisions of the brain are presented for the first time, and the relative size of the major brain divisions is similar to that of sturgeons and generalized sharks (such as hexanchids and squalids). Examination of brain component weight (s): body weight plots in a sample of non-teleost actinopterygian fishes indicates that all major divisions of the brain, except the telencephalon, are larger than in Latimeria. Brain component sizes in Latimeria are more similar to those extrapolated for amphibian brains than to those for actinopterygians. However, the cerebellum of Latimeria is considerably larger than that of amphibians.

Notes: The Champy-Maillet osmium tetroxide-zinc iodide technique and a new method using azur B-sodium thioglycolate were used to study the general nervous tissue structure in planarians. A subepidermal and a submuscular nerve plexus, partially reported by earlier authors, are described, and a gastrodermal plexus is reported for the first time in triclads. The possible functions for each one of these plexuses are discussed. By the Champy-Maillet method, the innervation within the parenchyma appears as an array of numerous single nerve fibers that course between the parenchyma cells making apparent synaptic contacts. The pharynx has outer and inner nerve nets similar in structure to the submuscular nerve plexus. Both nerve nets are connected to each other by radial nerves.The central nervous system has a sponge-like structure with many lacunae filled with cell bodies, dorso-ventral muscle fibers, parenchymal cell processes and excretory ducts. The existence of this sponge-like nervous tissue structure is discussed in relation to the still incomplete centralization of the nervous tissue in these organisms, to the lack of a true vascular system and to the acoelomate level of organization. A comparison with the nervous tissue structure of more advanced groups like polyclads and nemertines is suggested.

Notes: The gross morphology of the nervous system supplying the dorsal longitudinal flight muscles of tsetse flies is described. Electron microscopical investigation of the nerves reveals that the dorsal longitudinal muscles are innervated by branches from four main axons. A detailed description of the neuromuscular junctions in the flight muscle is presented.

Notes: Projection microradiography was used to determine the density and orientation of the force transmitting structures, i.e., trabeculae and bone lying between approximately parallel vascular canals, within the bones of cat skulls. The organisation in the skulls was confirmed statistically for a total of ten cats. The results of the observations showed that within specific areas of the skull a high degree of structural orientation and an increased density of osseous structures was present. The distribution of these characters corresponded in contiguous bones such that a continuum of structural organisation was established between the alveolar region and the site of attachment of the temporalis and masseter muscles and the glenoid region.The patterns of force transmission during jaw closure were determined when a resistance was placed initially between the canines and then the carnassials. An analysis was first carried out on dry skulls using colophonium resin to determine the direction of the force distribution. The nature and the approximate magnitude of the forces were ascertained by replacing the resin with strain gauges. The basic similarities in the strain patterns recorded from the dry skulls and those from the ten anaesthetised cats in which strain gauges had been intra-vitally implanted, substantiated the recordings made on the dry skulls. Combination of the results from the three sets of experiments defined the patterns of force distribution in the cat skull during the closure of the mandible against a resistance. The results showed that: (1) the combined action of the temporalis and masseter muscles tended to reduce the overall strain in the skull bones, and that the deformations produced by the action of the masseter were greater than that exerted by the temporalis muscles; (2) during biting, whether the resistance was placed between the canines or carnassials, compressive forces predominated in the facial bones; (3) small movements observed between facial bones indicated the presence of a flexible component within the skull, thus allowing large forces to be exerted during biting without overstressing the facial bones; (4) the glenoid fossa is part of a force bearing joint; (5) forces generated during biting were resisted within the skull by forces of an opposite nature generated within the system, the incompressible nature of bone and by the effect of the soft tissues; (6) the nature and the magnitude of the strain altered when a resistance was placed at the canines and then at the carnassials; however, the pattern of force distribution within the skull remained the same; (7) there was a direct correspondence between the detailed structural organisation of the bones and the patterns of force distribution. This conclusion would appear to apply in general to mammalian skulls. The study also emphasises the importance, neglected hitherto, of carrying out a variety of experiments to determine the patterns of force distribution in bones.The Trajectorial Theory of bone organisation is discussed and, on the basis of the results obtained, a modified theory is proposed. This states that: the structural continuum is common to the compact and cancellous bone and comprises bony bars which are aligned in the optimum direction for the transmission of force to a region in the bone or bones where it is effectively resisted.

Notes: There are two discrete lobes comprising the armadillo subman-dibular gland. These two lobes can be defined grossly, histochemically and morphologically with the light and electron microscope. The minor lobe stains more intensely with PAS and AB. When viewed in the electron microscope, the secretory granules of the acinar cells within this lobe appear mucous-like. The granules of the demilune cells are slightly different in appearance. The secretory granules of the acinar cells in the major lobe contain many dense foci embedded in a fibrillar matrix, a substructure not described previously. The demilune cells of this lobe contain secretory granules with a mucous-like structure which is consistent throughout the entire lobe. As in the minor lobe, these demilune cells stain very intensely with PAS and AB.

Notes: The relationship of the cells and tissues which comprise the developing ovarian follicle in Xenopus laevis has been studied with scanning and transmission electron microscopy. The saclike ovary is covered on its coelomic side by a squamous epithelium. The cells of this epithelium are extensively interdigitated, and each bears a short, centrally positioned cilium. The lumenal surface of the ovary is covered with a layer of nonciliated squamous cells. The areas of cell-cell contact are characterized by desmosomes in both epithelia, and between the epithelia lies a connective tissue layer-the theca-which contains collagen fibers, blood vessels, nerves, smooth muscle cells and oogonia. Beneath the theca in each follicle lies a single layer of flat stellate follicle cells. Associations between adjacent follicle cells are intermittent, leaving wide spaces or channels. Junctional contacts between neighboring follicle cells are characterized by desmosomes. From the basal surface of each follicle cell extend long, broad macrovilli which penetrate the underlying acellular vitelline envelope and contact the surface of the oocyte. Evidence is presented which suggests that follicle cells may produce and release components which participate in the formation of the vitelline envelope which consists of a 3-dimensional lattice of ropey fibers. Passageways through the vitelline envelope allow the maintenance of contact between oocyte and follicle cells and also allow ready penetration of materials both to the oocyte (e.g., vitellogenin) and from it (e.g., cortical granule material) at different stages of its development.

Notes: This study reveals age related changes in the microscopic structure of the paired frontal bone of the domestic rabbit. Undecalcified ground sections were prepared from anterior frontal bone slices removed from New Zealand White rabbits ranging from birth to 24 months of age. Included were 40 females, 4 males and 6 rabbits less than 14 days old of unknown sex. The ground sections revealed both qualitative and quantitative age changes. Qualitative changes include change in bone tissue types and developmental processes, and presence or absence of primary and secondary osteones. Quantitative changes were measured by counting primary osteones in the outer table of each frontal bone half within 1.6 mm of the metopic suture. In this region, primary osteones were absent at birth, limited in number at 14 days and generally numerous between one and three months of age. In animals older than three months, numbers of primary osteones generally decreased with increasing age. No animals older than 16 months revealed primary osteones. Possible sources of variability in the relationship between observed primary osteone number and age include ability to recognize primary osteones, methods of sampling and processing bone slices, sex related differences and diseases afflicting specimen. Significance of this study includes increased knowledge of frontal bone growth and histology.

Notes: The ascophoran Pentapora foliacea was studied from epoxy sections of skeletal and soft (hard-soft) tissues. The basal wall is double, indicating the colony grew as two independent layers, back to back. The structure of the vertical walls and interzooidal communication organs indicates that zooids were budded in the usual way as in most encrusting cheilostomes. Secondary layers of the frontal wall are of acicular aragonite. The ovicell develops as a flattened cuticular bladder in early ontogeny; the aragonitic layer of the frontal wall later engulfs it. A median vesicle, an evagination of the vestibular wall, is present but the eggs may be supplied with sufficient yolk to nurture the embryo. The overall ovicell structure is similar to that of hyperstomial ovicells in other cheilostomes.

Notes: This investigation describes the pre-natal morphogenesis of the type I pneumocyte subsequent to its differentiation from pulmonary epithelium. Cells lining subpleural alveolar septa were photographed from serial sections with the electron microscope, and a three-dimensional representation of each cell was obtained by transferring the contours of the cell membranes from montages to transparent plastic sheets which were then spaced to scale and stacked. The results of this study indicate that: The nascent blood-air barrier of a 50-day reconstructed cell was twice as thick as the average definitive barrier; definitive barrier thickness was observed in some areas in a 63-day reconstructed cell; the amorphous component of elastic tissue which appears peripherally in septal connective tissue during pre-natal morphogenesis may be directly juxtaposed to the basal lamina of the alveolar epithelium; the orientation of the cell junction between a pneumocyte and its neighboring cells, as observed in sections of alveolar septa, changes as the contour of the pneumocyte changes from simple abutment to overlapping patterns.

Notes: The fine structure of the mid-gut musculature of the desert locust, Schistocerca gregaria is described and compared with that of the visceral muscles of other species. The gross morphology and fine structure of the nervous system which supplies the mid-gut muscle fibres is described.

Notes: The integument of Paranthessius anemoniae has been studied with light and electron microscopy. A cuticle with clearly defined epicuticular, exocuticular and endocuticular regions overlies a cellular hypodermal layer. The distribution of carbohydrate, lipid and protein components of the cuticle were demonstrated histochemically. Parabolic striations in oblique sections of cuticle suggest that its molecular architecture fits a “twisted sheet” theory proposed for other species.Arthrodial membranes at body and limb joints have a homogeneous structure, lacking exocuticle and endocuticle. Subcuticular glands appear to secrete substances thought to be responsible for the immunity which Paranthessius seems to have to the nematocysts of its host. Small hairs, situated in cuticular cups which occur over the dorsal body surface are considered to function as rheoreceptors.

Notes: The larval epithelium of the sea urchin, Lytechinus pictus, consists of squamous cells and bands of columnar epithelial cells bearing cilia. During metamorphosis this tissue undergoes a series of rapid, complex changes. Through the scanning and transmission electron microscope, we describe and analyse these changes. The changes can be divided into three steps. (1) The larval arms bend away from the left side of the larva, exposing the urchin rudiment. Cells which are identical to smooth muscle cells are in a position to bring about this bending. (2) The squamous epithelial cells assume a cuboidal shape. This change in shape results in the collapse of the larval epithelium onto the presumptive aboral surface. These cells possess a subapical band of microfilaments. The cellular shape change but not the bending of the arms is reversibly inhibited by Cytochalasin B. These observations suggest a mechanism for this change. (3) The former lining of the vestibule of the urchin rudiment comes to lie over the collapsed larval tissue and forms the adult epithelium. At this point, after only one hour, the larva has assumed the external shape of an adult sea urchin.

Notes: This paper reports new observations obtained from a study of macronuclear fine structure throughout various stages of the cell division cycle of Euplotes. Study of the ultrastructural organization of the macronuclear chromatin indicates that much of the chromatin is organized into continuous masses, portions of which appear to be attached to the nuclear envelope. The macronuclear envelope appears unchanged in the region of a replication band, and apparent attachments of the chromatin to the inner membrane of the nuclear envelope are maintained in the reticular and diffuse zones. Intranuclear helices were never observed in the diffuse zone. During macronuclear division, linear elements (fibrils or microtubules) were observed in close association with both chromatin bodies and nucleoli. The ultrastructural data suggest that the intranuclear linear fibrils have two functions: elongation of the dividing nucleus, and attachment of chromatin bodies and nucleoli to the envelope. The significance of these observations for macronuclear division and chromatin segregation is considered.

Notes: The forelimbs of anteaters play a major role in obtainment of food, defense, and locomotion. The greatly enlarged claws on the manus are used for ripping open insect nests and insect-infested wood; the claws also serve as the animals' only defensive weapons, since they lack teeth. Specialization of the claws for these functions has also had a substantial effect on the ways in which the forelimb is used for posture and locomotion.Modifications of the forelimb in the anteater Tamandua include the following. Attachments of the medial head of triceps are rearranged so as to greatly increase capability for powerful flexion of the claws. Ability to flex the elbow and to retract the humerus is also augmented; these movements would assist digital flexion in applying traction with the claws to material being torn away during food procurement. This traction can be supplemented by a variety of powerful side-to-side and/or twisting movements of the hand, brought about primarily by axial rotation of the upper arm and forearm. The digital joints are reinforced to resist the deviational and torsional loading to which the digits would be subjected during such movements.The morphological modifications of the forelimb in Tamandua are discussed in terms of how they affect the mechanical capabilities of the limb, what functions the limb is best designed to perform, how they may relate to what little is known about the specialized behavior of this animal, and what behavioral predictions may be made based on mechanical design.

Notes: The olfactory system of the pigeon (Columba livia) was examined. Our electrophysiological and experimental neuroanatomical (Fink-Heimer technique) data showed that axons from the olfactory bulb terminated in both sides of the forebrain. The cortex prepiriformis (olfactory cortex), the hyperstriatum ventrale and the lobus parolfactorius comprised the uncrossed terminal field. The crossed field included the paleostriatum primitivum and the caudal portion of the lobus parolfactorius, areas which were reached through the anterior commissure. In this report the relationships between areas that receive olfactory information and the possible roles that olfaction plays in the birds' behavior are discussed.

Notes: Adult newts (Notophthalmus viridescens) were lentectomized and at intervals from 4 to 21 days after lentectomy iridocorneal complexes from these animals were examined by scanning electron microscopy to allow a full appreciation for the shape of the regenerating lens. Until around day 12 after lentectomy the posterior surface of the iris is covered by a dense mat of fibrous material which cannot be removed without damage to the iris and which obscures the events of cytoplasmic shedding. The regenerate becomes visible first around stage IV (day 12). A small but clear groove demarcates the regenerate from the rest of the iris. As regeneration progresses there is a marked reduction in debris on the iris surface and the regenerate appears as a U-shaped thickening occupying about one-third of the dorsal half of the iris. During later stages (VI-X) the regenerate protrudes into the pupil inferiorly and posteriorly towards the retina, but does not encroach laterally on the remaining pigmented iris tissue. Prior to secretion of the lens capsule the outline of individual cells is visible on the surface of the regenerate and some regenerates exhibit a prominent dimple on their posterior aspects. Following secretion of the capsule the surface of the regenerate becomes smooth. Quantitative studies show that volume and maximum section area of the regenerate are both more strongly correlated with developmental stage of regeneration than with time after lentectomy.

Notes: Secretion in the salivary glands of Gromphadorhina portentosa involves three cell types: parietal cells, secretory cells, and duct cells. The organization and role of the parietal and secretory cells are here considered. Parietal cells have numerous mitochondria, indicating an active metabolic role and the subsequent production of ATP. Plasma membrane invaginations and intracellular ductules containing microvilli appear to function in the absorption of solutes from the hemolymph and finely-tapered ductules. Secretory cells contain abundant rough endoplasmic reticulum, the three forms (stacked, vesicular, and diffuse) of which appear to develop sequentially during maturation. Secretory vesicle formation is asynchronous between adjacent secretory cells, and apparently the large vesicles often coalesce. The secretory vesicles also show differing degrees of electron density, indicating distinct biochemical composition.

Notes: Studies were undertaken of the microcirculation and histology of the gill of Protopterus aethiopicus as a prerequisite for elucidating the function of the gills in a bimodal respiratory system. The lamellae of the gill-bearing arches (I, IV, V, VI) resembles the arborescent external gill of the larval amphibian rather than the gill of the teleost or selachian.The arterio-arterial system (a-a) of the gill consists of an afferent artery, a series of large capillaries, and an efferent artery on each of the primary, secondary and tertiary lamellae. There are no pillar cells and the loose capillaries are covered with a multilayered epithelium. While living in water, the minimum distance for gas exchange is of the order of 5 μ. An afferent-efferent arterial shunt at the base of each primary lamella may be involved in control of lamellar blood flow and the resistance of the gill vasculature.The arterio-venous system originates primarily from the efferent side of the arterio-arterial system and drains into large branchial veins. Numerous contractile cisternae, interposed between intercellular channels and veins, presumably function as micropumps that collect fluid from intercellular epithelial spaces and inject it into the venous circulation.During aestivation, the epithelial layer of the gill lamellae becomes thinner. The entire gill vasculature, including the capillaries and afferent-efferent shunts on arches IV-VI, are very dilated which presumably promotes blood flow through these gill arches to the lungs.

Notes: The movements of the shoulder girdle of eight adult cats during overground stepping were studied, using standard slow motion cinematographic techniques. The patterns of activity of shoulder muscles were examined, using simultaneous intramuscular electromyography. Walking, trotting and galloping steps were analyzed from digitized single motion picture frame images. Angular movements of the shoulder girdle consist of biphasic flexion and extension of the shoulder joint and a monophasic flexion-extension alternation of the scapula on the thorax during each step cycle. In addition, the center of the scapula moves craniad during the swing phase and caudad during the stance phase with respect to a fixed reference point on the animal. Similar vertical movements of the center of the scapula also occur in each step cycle. Results of EMG studies of the 17 muscles capable of acting on the shoulder girdle indicate that three overall patterns of activity are found: (1) a pattern typical of extensor muscles, active during all the extension epochs; (2) a pattern typical of flexor muscles, active during the flexion epoch; and (3) a biphasic pattern of activity, active twice in each step. These data are used, along with a re-examination of previous models of the mechanics of the shoulder girdle of carnivores to examine the function and mechanics of shoulder motion. It is concluded that the rotary and translatory movements of the shoulder girdle during stepping combine to enhance step length.

Notes: The most striking morphological feature of the ovarian epithelium of Cymatogaster is the presence of intercellular dilations during much of the year. These dilations increase markedly in volume during the several months prior to ovulation and fertilization, and decrease in volume during the months of embryogenesis and gestation. The epithelium then returns to its initial, relatively undifferentiated state. The extracellular material within the dilations likely is synthesized in the cells adjacent to or within the dilations. Apparently most of this material is released into the ovarian lumen when the apicolateral margins of adjacent epithelial cells pull apart; possibly it serves as nutrient for developing embryos.In addition to supporting embryogenesis, the ovarian epithelium also apparently is involved in sperm storage. Sperm are maintained within pockets in the ovarian epithelium for the several months between insemination and fertilization. The cells lining the sperm pocket do not develop the intercellular dilations characteristic of most of the ovarian epithelium, and sperm remain associated only with the sperm pocket cells.

Notes: The histology and carbohydrate histochemistry of eight teleostean stomachs are compared. Three gross anatomical types of stomachs are described and their shapes appear to correlate somewhat with feeding habits. Each type can be divided histologically into a corpus and pylorus. Gastric glands, containing only one cell type, occur in the copora of all species, but are present in the pylori of esocids only. As a single cell can produce both enzymes and hydrochloric acid such cells may be comparable to those of amphibians but not mammals. Lamina propria and submucosa are indistinctly separated in corpora but better defined in pylori by an intervening muscularis mucosa. The arrangement of the muscularis into inner circular and outer longitudinal layers is the opposite of that seen in the esophagus. Gastric mucous cells show species variations in localization of epithelial mucosubstances, which in broad terms are recognized as sulfomucins, sialomucins and neutral mucosubstances. A piscivorous diet does not appear to demand any particular type of carbohydrate. Within the Centrarchidae, gastric pit cells vary in carbohydrate content from only neutral mucosubstance to only weakly acidic sulfomucin; two species contain both types. A positive PAS reaction on the surface of gastric epithelial cells is suggestive of a striated border and thus possibly absorptive function. The absence of stomachs in some teleosts and the evolutionary and dietary significances are discussed.

Notes: The American cockroach has a total of 368 muscles inserting on the post-coxal segments of its legs. By using a narrow morphological definition for delimiting individual muscles, it is shown (i) that the protrochanteral musculatures (23 muscles/leg) differ from the essentially identical meso- and metatrochanteral musculatures (24 and 26 muscles/leg) in number and disposition of extensors and in having a completely different flexor composition, and (ii) that the musculatures of the more distal segments of the legs are completely serially homologous, there being 2 muscles for moving each femur, 23 for each tibia, 7 for each first tarsomere, and 5 for each of the paired pretarsal claws. In all six legs, the trochanteral and tibial musculatures each contain single slender muscles that may be acting proprioceptively to measure the angular displacements between, respectively, the coxas and trochanters, and the femurs and tibias. Neurological and phylogenetic considerations are used to demonstrate why a narrow morphological definition should be employed, and why the widely used functional definition of Snodgrass ('35) is not only fallacious on evolutionary grounds, but also leads to making erroneous conclusions regarding the manner in which insect musculature is controlled by the insect central nervous system. Finally, it is hypothesized that the physiological limitations imposed by having an open circulatory system and the problems inherent in the neural control of large muscles may have been major evolutionary factors in forcing insects to use many slender muscles to control their body movements.

Notes: Studies of the response of adult mammalian and amphibian ventricle to injury have indicated the formation of a connective tissue scar in the place of the wounded or amputated muscle. It has been demonstrated that amphibian myocytes adjacent to a wound surface, unlike mammalian myocytes, have a proliferative capacity. In the present study, a minced cardiac muscle graft was placed into the adult newt ventricle in order to increase the number of myocytes near a wound surface. With such an increased number of reactive myocytes, it was thought a new wall consisting primarily of muscle might be formed. One-sixteenth to one-eighth of the ventricular apex was removed, minced and returned to the amputation surface of the ventricle. General histological and autoradiographic studies were conducted on two sham-operated animals and on five experimental animals which were killed at 5, 10, 20, 30, 50 and 70 days after surgery. Major events of the repair and reorganization of minced cardiac muscle included blood clot formation followed by necrosis of the blood clot and much of the muscle graft. By ten days, an apparent coalescence of muscle fragments and continuity of ventricular and graft lumina were observed, although the graft area never formed an integrated unit with the wounded ventricular wall. The peak of mitotic activity (3.19%) and thymidine labeling (28.1%) of graft cells, including many cells which resembled cardiac myocytes, was observed at 20 days. At 30 days, the graft was observed as a continuous wall composed primarily of muscle fibers. Several 30-, 50- and 70-day grafts had rhythmic contractions. These results suggest that amphibian cardiac muscle has histogenetic and proliferative capacities not attributable to mammalian cardiac muscle.

Notes: The ultrastructure of the femoral extensors of the metathoracic leg of the cockroach, Periplaneta americana was studied to determine morphological correlations with the known patterns of innervation, physiological properties and biochemical properties. Three different types of muscle fibers were described. Type 1 consisted of short sarcomeres (mean 3.7 μm), few mitochondria and sparse glycogen-like material; Type 2, short sarcomeres (4.2 μm), numerous mitochondria, large amounts of glycogen; Type 3, long sarcomeres (7.5 μm), numerous mitochondria and large amounts of glycogen. A qualitative examination of the sarcoplasmic reticulum (SR) and transverse tubular system (TTS) revealed the density of SR and TTS to be greatest in Type 1 and least in Type 3. There were obvious correlations between the morphological features and the other known characteristics of these muscle fibers. The role of these different muscle fiber types in different locomotory behaviors was discussed. In summary, the three types of muscle fibers are used in three different behaviors: Type 1, rapid walking; Type 2, slow walking; Type 3, postural control.

Notes: An ultrastructural comparison of mouse oocytes isolated at various stages of growth and meiotic competence has been carried out. Progressive changes in the nucleoli, ribosomes, mitochondria, endoplasmic reticulum, Golgi complex, and other organelles and inclusions of the oocyte have been examined as a function of oocyte size by transmission electron microscopy. The observations presented support the idea that growth of the mammalian oocyte involves not just tremendous enlargement of the cell, but extensive alterations in its overall metabolism as reflected in the ultrastructure of the oocyte at various stages of growth.

Notes: Scale neogenesis following excision of pieces of skin of various sizes and shapes has been studied in several squamate species. In small wounds, neogenesis does not occur, the wound region contracts, and increased areas of hinge differentiation are seen. In large wounds, the time taken for neogenesis to occur, and the size, shape, distribution, and number of the reformed units, are variable. We confirm previous reports that neogenesis accompanies a renewal phase of the shedding cycle, and suggests that this is because both types of morphogenesis require germinal stability.All types of trauma thus far studied show the initial formation of a hyperplastic wound epithelium with the histological characteristics of a normal α-layer: such tissues are the basis for physiological barrier functions. The mechanical functions of the skin can be fairly adequately restored even by abnormal neogenic scales. The observed variability in the process of scale neogenesis, and the final form of the individual units, are argued to be the result of mechanical factors impinging on the differentiating tissues.

Notes: The stages in wound healing of the wax-moth, Galleria mellonella, were examined using routine histological techniques. Final instar larvae were wounded and maintained for up to 72 hours before fixation, dehydration and embedding in Paraplast wax or Araldite.Immediately after wounding both fat-body and hemolymph were forced through the wound to form a plug. Concomitantly, the hemolymph coagulated forming vast networks of strand-like material attached to the hemocytes underlying the wound. After one to two hours this plug melanized and the cells became highly necrotic. Six hours after wounding, there was a massive influx of hemocytes which eventually attached to the melanized layer over the wound to form a multicellular sheath. Twelve to twenty-four hours later, the epidermal cells underlying the broken cuticle detached and migrated across the wound to form a new intact layer. This layer secreted an amorphous material which is probably the precursor of the new cuticle. Hemocyte functions during wound healing and other cellular defenses are discussed.

Notes: Time-lapse cinemicrography was used to show what changes in the number, size, shape, arrangement and what movements of apices of superficial cells occur during epiboly, extension, convergence and blastopore formation in the blastula or gastrula of Xenopus laevis. Epiboly of the animal region occurs by apical expansion of superficial cells at a nearly constant rate from the midblastula to the midgastrula stage. Egression of deep cells into the superficial layer does not occur. Extension of the dorsal marginal zone begins in the late blastula stage with the rapid spreading of the apices of cells in this region and this continues until the onset of neurulation when rapid shrinkage begins. Extension and convergence of the dorsal marginal zone occurs by a rearrangement in which individual cells exchange neighbors and by a change in the shape of the cell apices. Regional differences in apical expansion are accompanied by differences in rate of anticlinal division of superficial cells such that cells in all sectors of the animal region and the marginal zone show similar patterns of decrease in apparent apical area. Shrinkage of the apices of bottle cells during blastopore formation is described. From this and other studies, a model of the cellular behavior of epiboly, extension and convergence is constructed and several hypotheses as to how these activities might generate the mechanical forces of the gastrulation movements are presented.

Notes: The digestive tract of Hoplosternum thoracatum consists of an esophagus, gastric area, anterior digestive intestine with elaborate folds, digestive intestine with decreasing folds and thin, smooth-surfaced respiratory intestine. The upper tract has a mucoid columnar lining which is gently folded, whereas the gastric area has numerous pits opening into the tubular secretory glands. Striated muscle comprises the anterior muscularis but is replaced by inner circular and outer longitudinal smooth muscle layers in the gastric region. The digestive intestinal mucosa is elaborately folded, consisting of columnar cells with prominent brush borders. Mucosa, submucosa, circular and longitudinal muscularis and serosa layers are present throughout the tract. Goblet cells occur in both the digestive and respiratory intestine. Major changes that appear in the respiratory intestine are a drastic reduction in mucosa epithelial thickness and the penetration of an elaborate capillary bed into the epithelium. The other basic layers are not significantly reduced in thickness. The air-blood barrier consists of the thin epithelium, basement lamina and very thin capillary endothelium. Regional cellular composition and ultrastructural features are correlated with respective digestive and respiratory functions.

Notes: The morphology and microscopic anatomy of the reproductive organs and colliculus seminalis of the male rabbit are described and illustrated. Special attention is given to the accessory sex glands, because not all have been accurately identified previously. The terminology suggested for the accessory glands (with other terms commonly used in the literature in parentheses) follows: glandula vesicularis (glandula seminalis, vesicula seminalis), proprostata (glandula vesicularis, coagulating gland, prostata), prostata, paraprostata (glandula Cowperi superior), glandula bulbourethralis (glandula Cowperi inferior). The English equivalents are vesicular, proprostate, prostate, paraprostate and bulbourethral glands. Organs were obtained from 39 adult Dutch-belted rabbits that averaged 2,023 g in bodyweight. Organ weights (means and standard deviations) were as follows: testis, 2.035 ± 0.529 g; caput epididymidis, 0.264 ± 0.087 g; corpus epididymidis, 0.046 ± 0.019 g; cauda epididymidis, 0.398 ± 0.123 g; proximal part of the ductus deferens, 0.098 ± 0.026 g; ampulla of the ductus deferens, 0.177 ± 0.069 g; vesicular gland, 0.529 ± 1.169 g; proprostate gland, 0.633 ± 0.304 g; prostate gland, 0.411 ± 0.181 g; paraprostate gland, 0.040 ± 0.019 g; bulbourethral gland, 0.390 ± 0.133 g; and epididymal fat pad, 0.545 ± 0.339 g. Correlations among organ weights were calculated and interrelationships among them and bodyweight are discussed.

Notes: Early embryonic mitosis of the silkworm, Bombyx mori, was morphologically studied in the normal eggs and in the eggs treated by low temperature (-10°C).The first embryonic mitosis is observed in the eggs at 120 to 150 minutes after deposition at 26°C. After egg and sperm pronuclei unite, a spindle is formed in each of the pronuclei independently. At metaphase and anaphase paternal and maternal chromosomes are in separate groups on a spindle (gonomeric) and karyogamy takes place at telophase when they reach the poles.The second embryonic mitosis is shown in the eggs at 180 to 210 minutes after deposition. The division of two nuclei is not synchronous in the silkworm, and the mitosis is not gonomeric.In the eggs treated by low temperature, spindle fibers are not observed at all at -10°C, and chromosomes, which form two deeply stained masses of irregular shape, are seen in the less stained area of spindle shape. When the eggs are returned to 26°C, some eggs go into normal gonomeric division, while some form two small and compact spindles, which seem to be derived from each of the pronuclei. It was observed that these compact spindles are able to continue mitosis.

Notes: Ultrathin sections of the nasal barbel of the channel catfish, Ictalurus punctatus, were studied in the electron microscope and the fine structure was compared to that of barbels of other teleosts and to the mandibular (dentary) barbels of I. punctatus. While the overall histology of the nasal barbel is similar to that of barbels described previously, this study revealed far greater cellular complexity and variability than was previously reported. A layer of stratified epidermal cells rests upon a connective tissue dermis containing a cartilage rod, a large number of nerve fibers and numerous blood vessels, fibroblasts and pigment cells. Taste buds are present in the epidermal layer. This layer was found to contain probably 16 kinds of cell types, several of which may represent transitional stages, in addition to taste bud cells. Observations were made pertaining to innervation and cell types in the taste buds. A new terminology for designating the barbels of I. punctatus is suggested.

Notes: Tibiotarsal segments of 12-day chick embryos homozygous for the crooked neck dwarf gene (cn/cn) were examined histologically following routine methods of preparation. The myogenic mass fails to divide into separate muscle bundles during the early stages of differentiation. Myoblasts and myotubes are observed, although the proportion favors the mononucleate cell population. Multinucleate myotubes are often wavy in appearance and many contain eosinophilic cytoplasmic inclusions. The entire tissue mass of mutants appears more compacted than in control limbs. Poor organization of muscle appears related to the lack of a suitable connective tissue system. Epimysia, perimysia, and subcutaneous connective tissue fail to develop properly. Tendons are poorly developed or absent. Comparisons between mutant and control embryos show no differences in peripheral innervation. Nerve fascicles penetrate deeply into the developing muscle of both species. The distribution of vascular elements is seemingly normal also. Skeletal muscle of cn/cn embryos is capable of differentiating to the myotube stage, after which it undergoes cellular degeneration without achieving a functional state. Comparisons of this mutant with alleged chemical phenocopies show important differences.

Notes: Die in situ durch Einwirkung von Acetanhydrid oder Dicyclohexylcarbodiimid auf die Phenyl(thiocarbonyloxy)essigsäuren 2a-e bereiteten mesoionischen 1,3-Oxathiolone 6 nehmen als cyclische Carbonyl-ylide in 2,5-Stellung Acetylendicarbonsäure-dimethylester unter Bildung nichtisolierbarer Primäraddukte vom Typ 7 auf. Letztere fragmentieren rasch unter Kohlenoxisulfid-Abspaltung in die Furancarbonester 8a-e (37-87%). Die entsprechenden in situ-Cycloadditionen von 6 an Propiolsäure-methylester, Phenylpropiolsäure-methylester, Acetylphenylacetylen bzw. Dibenzoylacetylen liefern die Furan-Abkömmlinge 8f-p (Tab. 1). Weiterhin bildet 2d in Ether mit Acetanhydrid und Perchlorsäure das neue isolierbare 1,3-Oxathiolyliumperchlorat 3, aus dem der mesoionische Aromat 6 mit Triethylamin in situ generiert wird; dieser reagiert in Gegenwart von Acetylendicarbonester zum bereits aus 2d erhaltenen Furan-Derivat 8d. Die Furan-Konstitutionen sind mit spektroskopischen Daten in Einklang.

Notes: Die Titelverbindung entsteht aus Kupfer(I)-trimethylsiloxid durch thermische Abspaltung von Hexamethyldisiloxan. Ihre Struktur wurde röntgenographisch bestimmt (Raumgruppe C 2/m, Z = 2) und bis R = 0.079 verfeinert. Die Verbindung stellt ein voluminöses, kugelförmiges Molekül dar, das im inneren Teil achtzehn über Sauerstoff verbrückte Cu-Atome enthält. An der Oberfläche des Moleküls befinden sich vierzehn Trimethylsilylgruppen.

Notes: Durch Umsetzung von [IrCl(CO)L2] (L = PPh3, PMePh2, PEt3) mit den entsprechenden Lithiumarylen wurden ortho-substituierte Tolyl-, Xylyl- und Mesitylkomplexe des Typs [Ir(MenC6H5-n)(CO)L2] (MenC6H5-n = 2-MeC6H4; 2,3-Me2C6H3; 2,4-Me2C6H3; 2,6-Me2C6H3; 2,4,6-Me3C6H2) dargestellt. Mit Ausnahme von [Ir(2,6-Me2C6H3)(CO)(PPh3)2] und [Ir(2,4,6-Me3C6H2)(CO)(PPh3)2], welche cis-trans-Isomerie zeigen, erweisen sich diese Verbindungen aufgrund ihrer 1H-NMR- und 31P-NMR-Spektren als trans-konfiguriert. Am Beispiel des Komplexes cis-[Ir(2,4,6-Me3C6H2)(CO)(PPh3)2], der mit Phosphinen PR3 unter Bildung von trans-[Ir(2,4,6-Me3C6H2)(CO)(PR3)2] (PR3 = PMe3, PEt3, PMe2Ph. PMePh2) reagiert, wird gezeigt, daß Phosphin-Austauschreaktionen unter Erhalt der Aryl-Iridium(I)-Gruppierung verlaufen. Dagegen führt die Reaktion von [Ir(MenC6H5-n)(CO)L2] mit Phosphiten P(OR)3 zu dreifach substituierten Produkten, welche aufgrund ihrer IR-, 1H-NMR-, 13C-NMR- und 31P-NMR-Spektren als cyclometallierte Hydridoiridium(III)-Komplexe des Typs -{P(OR)3}3 [2-CH2C6H5-nMen-1 = 2-CH2C6H4; 2-CH2C6H3Me-(3); 2-CH2C6H3Me-(4); 2-CH2C6H3Me-(5); 2-CH2C6H3Me-(6); 2-CH2C6H2Me2-(4,6); P(OR)3 = P(OMe)3, P(OEt)3, P(OPh)3] zu formulieren sind; d. h. durch den Austausch der Carbonylgruppe und der beiden P-Donorliganden L von [Ir(MenC6H5-n)(CO)L2] gegen drei P-Donatoren P(OR)3 werden unter milden Bedingungen ablaufende intramolekulare oxidative Additionen zwischen den C — H-Bindungen der ortho-Methylsubstituenten und dem Zentralmetall ausgelöst. Diese ungewöhnliche ligandeninduzierte Metallierung von Methyl-C — H-Bindungen wird diskutiert und mit einigen vermutlich verwandten ortho-Metallierungsreaktionen aromatischer C — H-Bindungen verglichen.

Notes: Die Ozonide 5, 11 und 18 reagieren wie die als Zwischenprodukte auftretenden 1,4-Diketone mit Lithiumaluminiumhydrid zu Gemischen von d, l- und meso-Diolen. Die an den NMR-Signalen für die diastereotopen Methylgruppen ablesbaren Stereoselektivitäten für d, l- und meso-Formen werden mit einer intramolekularen Diastereoface-Differenzierung auf der Stufe der Ketoalkohole und der intermediären Ausbildung von Komplexen des Typs 36 (cyclisches Modell) gedeutet. Die stereochemischen Analyse wird durch die ohne Konfigurationsänderung ablaufende Über-führung der Diole in die entsprechenden cis, trans-isomeren Ketale bzw. Acetale bestätigt. Wasserabspaltung aus den zweiwertigen Alkoholen führt nach Art einer nucleophilen inneren Substitution stereospezifisch zu cis, trans-isomeren cyclischen Ethern.

Notes: N, N′-Di-tert-butylschwefeldiimid (1) reagiert mit den Isocyanaten n-C4F9SO2NCO. 3-ClC6H4NCO, 3-CF3C6H4NCO, CH3C(O)NCO, (O)PCl2NCO und SO2(NCO)2 unter (CH3)3-CNCO-Abspaltung zu 2a-e und 5. Die Bildung zwitterionischer Zwischenstufen konnte nicht beobachtet werden. 5 ist der erste acyclische Vertreter, bei dem zwei Schwefeldiimidgruppen über eine SO2-Gruppe verbrückt sind. Diese Austauschreaktionen verlaufen nur mit Isocyanaten, die elektronenziehende Substituenten enthalten. Die Chloratome in 2e können gegen Fluoratome (→ 3) oder Dimethylaminogruppen (→ 4) ausgetauscht werden.

Notes: Vanadocen-monohalogenide ergeben gut aufgelöste paramagnetische 13C- und 1H-NMR-Spektren. Testmoleküle sind neben (C5H5)2 VCl (1) die bisher unbekannten Vertreter (RC5H4)2 VX [R = CH3 (2) und C2H5 (3) mit X = Cl sowie R = CH3 mit X = Br (4) und I (5)], die aus entsprechenden Vanadocenen und Alkylhalogenid oder Iod hergestellt werden. Es wird eine Systematik von NMR-Verschiebungen gewonnen, die eine schnelle Strukturaufklärung in Lösung ermöglicht. Aus den Verschiebungen wird die Elektronenspindichteverteilung abgeleitet und auf vorwiegend π-Delokalisierung zweiter Ordnung zurückgeführt. Die NMR-Spektren von 3 bei variierter Temperatur zeigen, daß im Gegensatz zu (C5H5)2 TiCl keine Neigung zu Dimerisierung in Lösung besteht.

Notes: Die Kristallstrukturen der Komplexe [(CO)4M-P(CH3)2]2 (1, M = Mn; 2, M = Cr; 3, M = V), von denen 3 neu dargestellt wurde, wurden bestimmt. Die Komplexe haben als gemeinsames Merkmal die zentrosymmetrische bioktaedrische D2h-Struktur und als wesentlichen Unterschied die von 1 über 2 nach 3 zunehmende Metall-Metall-Wechselwirkung, die sich an den Abständen Mn—Mn (367.5 pm), Cr—Cr (durchschnittlich 290.5 pm) und V-V (durchschnittlich 273.3 pm) zeigt. Die von der 18-Elektronen-Regel für 3 geforderte V-V-Doppelbindung führt infolge intramolekularer sterischer Hinderung nicht zu einem deutlichen Unterschied im Molekülgerüst von 2 und 3. Strukturvergleiche und spektroskopische Daten belegen jedoch die verschiedene Elektronenstruktur der drei Verbindungen.

Notes: 1,5-Anhydro-4,6-O-benzyliden-2-desoxy-D-erythro-hex-1-en-3-ulose (1) reagiert mit 2-Lithio-1,3-dithiolan-2-carbonsäure-ethylester (2) unter 1,4-Addition zu den Oct-2-ulosonsäuren 3 und 6. In 6 wird die Konfiguration an C-6 während der Reaktion umgekehrt. Die Struktur von 6 wird durch Röntgenstrukturanalyse gesichert. Durch eine Folge von Reduktions- und Deblockierungsschritten werden aus 3 und 6 Oct-2-ulosen erhalten: aus 3 die D-allo- und D-gluco- 10 und 14, aus 6 die D-talo- und D-ido-Verbindung 18 und 22. Das Enon 1 reagiert mit Methylamin und Dimethylamin zu ringgeöffneten Enaminketonen 23 und 24.

Notes: A New Atractyligenine Glycoside from Green Coffee-beansA so far unknown glycoside was isolated from green coffee-beans. Its structure was determined by spectral data and chemical reactions to be 2-O-(2-O-isovaleryl-β-D-glucopyranosyl)atractyli genine (4).

Notes: The He(I) Photoelectron Spectrum of 1,2,6,7-Cyclodecatetraene. Evidence for a Strong Transannular InteractionThe photoelectron spectrum (He(I)) of 1,2,6,7-cyclodecatetraene (3) is discussed. The first four bands in the PE spectrum of 3 are assigned by comparison with calculated orbital energies according to MINDO/3. The interaction between both allenic units can be described by the interaction parameters β = -0.58 eV and β′ = -0.07 eV.

Notes: Synthesis and Cycloadditions of 1,5-Bis(3,5-dioxo-Δ1-1,2,4-triazolin-4-ylmethyl)-2,4-dimethylbenzeneThe synthesis and properties of the title compound 3 are described as well as its (4 + 2)-cycloadditions with cyclic dienes and anthracene to give the bis-adducts 4-6. With the bis(9-anthryl-methylthio)alkanes 7, 8 the macrocyclic phanes 9 and 10 are formed.

Notes: Die Umsetzung der Pentacarbonyl(ethoxyferrocenylcarben)-Komplexe von Chrom, Molybdän und Wolfram mit Bor- bzw. Aluminiumhalogeniden (MX3 mit X = Cl,Br) führt bei tiefer Temperatur zu trans-Halogenotetracarbonyl(ferrocenylcarbin)-Verbindungen (1-5). Durch eine Halogenaustauschreaktion an den trans-Bromotetracarbonyl(ferrocenylcarbin)-Komplexen mit LiI gelangt man zu den Iodhomologen 6, 7. Ergebnisse der spektroskopischen und elektrochemischen Untersuchungen der neuartigen Verbindungen sowie die Röntgenstrukturanalyse von 2 werden mitgeteilt.

Notes: Trimethylsilylmethyl-Gruppen stabilisieren als Donatorsubstituenten insbesondere Radikalkationen. Dies verdeutlichen die teils ungewöhnlich niedrigen 1. und 2. Ionisierungsenergien (H3C)3SiCH2-substituierter Benzole, die sich mit einem erweiterten Störungsmodell parametrisieren und mit den 1. und 2. Charge-Transfer-Anregungsenergien ihrer TCNE-Komplexe korrelieren lassen. Geeignet substituierte Benzolderivate, deren 1. Ionisierungsenergie 7.8 eV unterschreitet, können mit AlCl3 in H2CCl2 selektiv oxidiert werden. Hochaufgelöste ESR-Spektren belegen Spindelokalisation und liefern  -  zusammen mit PE- und CT-Spektren  -  zusätzlich Informationen über die Vorzugskonformation sowie über die Beweglichkeit der Substituentengruppen in den sterisch überfüllten Benzol-Radikalkationen.

Notes: Einelektronen-Oxidation mit AlCl3 in H2CCl2 ermöglicht es, die nur bei tiefer Temperatur existenzfähigen Radikalkationen von 4,4′-Bis(trimethylsilylmethyl)biphenyl (2), 9,10-Bis(trimethylsilylmethyl)anthracen (1) und 9,10-Bis(trimethylsilyl)-9,10-dihydroanthracen (3) zu erzeugen. Ihre hochaufgelösten ESR-Spektren lassen sich mit HMO-Modellen zuordnen und belegen weitgehende Spindelokalisation sowie eingeschränkte konformative Beweglichkeit. Für das 9,10-Dihydroanthracen-Derivat wird ein Diederwinkel von ≍ 125° abgeschätzt.

Notes: Durch [2 + 2]-Photoaddition von Diphenylacetylen (1) an elektronenreiche Cycloalkene 2, 5 werden cis-verknüpfte Addukte erhalten, die größtenteils auch durch NBS- und Pyridinbehandlung von Stilbenaddukten gewonnen werden. Die UV- und Fluoreszenzspektren sowie Photolyseergebnisse werden im Hinblick auf interne partielle Rotationsmöglichkeiten der Phenylgruppen analysiert und mit einer Reihe weiterer 1,2-Diphenylcyclobuten-Derivate 8-15 verglichen. Die Photoselektivitäten können an Hand der Ausbeuteverhältnisse unter verschiedenen experimentellen Bedingungen und zusammen mit Quantenausbeutemessungen verstanden werden: Bei unbehinderter partieller Rotation tritt α-Spaltung, bei sterischer Fixierung der Schraubenkonformation des Chromophors Cyclisierung zu instabilen 4a,4b-Dihydrophenanthren-Derivaten ein. Nur beim Zwischenprodukt 19, wird die schnelle [4 + 4]-Cycloreversion zum monocyclischen Dien 17 (indirekte β-Spaltung) beobachtet. In anderen Fällen lassen sich entsprechende [4 + 4]-Reaktionen photochemisch erzwingen. Es gibt keine Anhaltspunkte für direkte photochemische β-Spaltungen.

Notes: 4,6-Diamino-4,6-didesoxy-D-galactose liegt als Dihydrochlorid in der Pyranoseform 7 vor. Als freie Base bildet sie spontan die 1,6-Anhydro-α-D-galactofuranose-Form 6 mit zwei stickstoffhaltigen Ringen. Vom N,N-Diacetyl-Derivat von 6 werden die vier Rotationsisomeren 9 bis 12 beobachtet.

Notes: Die thermische Isomerisierung der Vinyloxirane 8-13, 15 und 17-20 zu den Dihydrofuranen 21-27 wird beschrieben. Je nach Art der Substitution lassen sich die Ringerweiterungsreaktionen bevorzugt in Lösung oder in der Gasphase (Kurzzeitpyrolyse) mit Ausbeuten von 50-95% durchführen. Während 8-13, 15, 17 und 19 unabhängig von der Konfiguration des Oxiranrings stereoselektiv zu cis-2,3-Dihydrofuranen (21-23 und 25-27) umgewandelt werden, führt die Thermolyse des Diesters 18 zu einem 3:2-Gemisch der cis-trans-Isomeren 24c und 24t. Als Mechanismus der Vinyloxiran-Dihydrofuran-Isomerisierung wird eine zwei- oder mehrstufige Reaktionssequenz über 2-Oxapentadienyl-Dipole als Zwischenstufen vorgeschlagen, wobei der jeweils erste (C/C-Spaltung des Oxiranrings) und letzte Schritt (Cyclisierung des 1,5-Dipols) stereochemisch einheitlich erfolgen (die nur geringe Stereoselektivität bei der Reaktion von 18 wird auf einen erhöhten Diradikalcharakter der geöffneten Spezies zurückgeführt). Im Falle der Diastereomeren-Paare 8/9, 10/11 und 12/13 ist neben der Umwandlung zu Dihydrofuranen eine vorgelagerte cis ⇄ trans-Isomerisierung zu beobachten. Die Aktivierungsparameter der Umwandlungen 12/13 → 23 und 15 → 26 werden bestimmt und im Zusammenhang mit denen der Grundkörperreaktion diskutiert. Cycloadditionsexperimente mit 8-13 liefern 1 : 1-Addukte mit vollständiger oder weit überwiegender „Inversion“ der Konfiguration von Aryl- und Vinylrest: cis(trans)-Vinyloxirane führen zu 2.5-trans (cis)-Dihydro- bzw. Tetrahydrofuranen. Das Dinitril 20 als das thermisch labilste Vinyloxiran in dieser Reihe reagiert mit En-Komponenten nur unter drastischen Bedingungen und in besonders niedrigen Ausbeuten: ebenso wie in den anderen Beispielen fungiert hierbei das intermediäre 6-Elektronensystem ausschließlich als 1,3-Dipol ([4 + 2]-Addition), nicht aber als 1,5-Dipol ([6 + 2]-Addition).

Notes: Quadratsäure zeigt gegenüber Pt0-Verbindungen drei Reaktionsmöglichkeiten: Der Säurecharakter der Quadratsäure kommt bei der Bildung des kationischen Hydridkomplexes [HPt(PPh3)3]⊕ [HC4O4]⊖ (1) aus Pt(PPh3)4 zum Ausdruck; mit (PPh3)2Pt(C2H4) entsteht dagegen der Olefinkomplex 2. Erhitzen von 1 bzw. 2 auf 130°C liefert unter Öffnung des Vierrings das Dihydroxyplatinacyclopentendion 3.

Notes: Die Abspaltungsgeschwindigkeit aliphatischer Basenschutzgruppen bei Derivaten des 2′-Desoxycytidin-5′-monophosphats wird bei verschiedenen pH-Werten UV-spektroskopisch gemessen. Verzweigte, raumerfüllende Schutzgruppen zeigen erhöhte Stabilität. Propionyl wird überraschenderweise schneller entfernt als Acetyl.

Notes: Transition Metal Carbyne Complexes, XLIII: Reduction of a Metal-Carbon Triple BondReaction of [π-C5H5(CO)2ReCC6H5]+[BCl4]- with Et2AlH yields  -  depending on reaction conditions  -  the novel secondary carbene complex π-C5H5(CO)2ReCHC6H5 (2) or the σ-benzylhydrido complex π-C5H5(CO)2HReCH2C6H5 (3). The reaction is the first example of a stepwise reduction of a metal-carbon triple bond to a single bond.

Notes: 2-Oxo-2H-1-benzopyran-3-carbonsäureester gehen beim Erhitzen mit Acetanhydrid in Anwesenheit von Natriumacetat oder Triethylamin in die entsprechenden 2-Oxo-4-chromanessigsäureester über. Mit den Anhydriden anderer Carbonsäuren werden die Ester von 3-substituierten 2-Oxo-4-chromanessigsäuren erhalten. Der Mechanismus dieser bisher unbekannten Umwandlung wird diskutiert.

Notes: Bei der Behandlung der 3H-Indole 6a-h mit 3-Chlorperbenzoesäure können die primär gebildeten 7,7a-Dihydrooxazirino[a]indole 7a-h nicht gefaßt werden, da sie spontan in 35-85proz. Ausbeute in die Indolinone 4a-h und die Isocyanate 9a-h übergehen. Letztere werden entweder als solche oder in Form von Derivaten isoliert bzw. charakterisiert. Dieses Umlagerungsmuster ist für 7a-unsubstituierte, aber 3-substituierte 7,7a-Dihydrooxazirino[a]indole typisch. Deuteriummarkierung an C-2 von 6a verringert den Anteil der durch H-Verschiebung entstehenden Produkte 4a und 9a zugunsten des Ringerweiterungsproduktes 11 und beweist, daß das benzylische H-Atom in 9a von C-2 des eingesetzten 6a stammt.

Notes: Dithiobis(dimethylphosphin), [(CH3)2PS—]2, konnte durch Komplexierung mit η5-C5H5Mn(CO)2 erstmals stabilisiert werden. Die Titelverbindungen 1 und 2 kristallisieren orthorhombisch bzw. monoklin in den Raumgruppen Iba 2 bzw. C 2/c mit Z = 8. Die Mn — P-Bindungen in 1 und 2 besitzen mit 218 pm beachtlichen π-Bindungscharakter. Der Torsionswinkel in 1 beträgt 120°.

Notes: Das Hydrido-cyclotri(phosphazen) 1 addiert Chlorphosphine 2 unter PP-Verknüpfung zu Hydro-chloriden 3 von Phosphino-cyclotri(phosphazenen) 6, aus denen mit NH3 diese selbst freigesetzt werden können.  -  Mit dem bifunktionellen Dichlormethylphosphin (9) und auch mit Tris(dimethylamino)phosphin kommt eine PPP-Verknüpfung zweier Phosphazenringe über eine Phosphinobrücke zustande.

Notes: Schiffsche Basen ArRC = NR′ 1 bzw. 8 bilden mit (Me3Si)2Hg beim Erwärmen oder Belichten spontan und glatt die Radikale ArRC· — NR′SiMe3 3 bzw. 9. Diese stehen im Gleichgewicht mit den entsprechenden Dimeren, den 1,2-Diaminoethanen 4 bzw. 10. Die Gleichgewichte sind stark abhängig vom sterischen Druck in den Dimeren. Mit R = Me isoliert man jedoch schließlich quantitativ die Produkte der Disproportionierung 6 und 7. ESR-Daten von 3 und 9 werden angegeben. Sie werden beeinflußt von der Raumerfüllung am C- und N-Atom.

Notes: 4,6-Di-O-acetyl-3-azido-1,2,3-tridesoxy-D- arabino-hex-1 enopyranose (1) addiert Nitrosylchlorid zum dimeren 4,6-Di-O-acetyl-3-azido-2, 3-didesoxy-2-nitroso-α-D-gluco-hexopyranosylchlorid (2). das mit Isopropylalkohol in DMF die beiden Glycoside 3 und 6 bildet. Durch zweistufige Reduktion mit Diboran/THF und Palladium/H2 entsteht stereoselektiv aus 3 das 2, 3-Diamino-2, 3-didesoxy-β-D-mannosid 5 und aus 6 das 2,3-Diamino-2,3-didesoxy-α-D-glucosid 8. Mit LiAlH4 entsteht aus 6 neben 8 das isomere 2,3-Diamino-2,3-didesoxy-α-D-mannosid 9. Aus dem dimeren Chlorid 11 werden die E- und Z-Oximino-α-D-glycoside 13a und 13b als Hauptprodukte, die entsprechenden β-Anomeren 12a und 12b als Nebenprodukte erhalten. Durch sukzessive Reduktion des Gemischs aus 13a und 13b mit Diboran und Palladium/H2 ist stereoselektiv das 2,3-Diamino-2,3-didesoxy-α-D-allosid 15 zugänglich, durch Reduktion mit LiAlH4 wird daneben das 2,3-Diamino-2,3-didesoxy-α-D-altrosid 16 gebildet. Analog zu 15 wird das Disaccharid 26 dargestellt.

Notes: Bei der Synthese des trans-2,3,4-Trihydroxyzimtalkohols (1) aus 4-Allylpyrogallol (6) wird die Seitenkette durch stereoselektive Reduktion der diastereomeren Bromepoxide 13 mit Zink erzeugt. Der extrem empfindliche Trihydroxyzimtalkohol 1 liefert bei der Oxidation mit Kaliumiodat oder Fruchtkörper-Extrakt von Fomes fomentarius das Purpurogallinderivat Fomentariol (2). Diese Reaktion kann als Modell der Biosynthese von 2 angesehen werden. Das neue Verfahren zur Zimtalkoholsynthese wird auch zur Darstellung von trans-o-Hydroxyzimtalkohol (22) aus o-Allylphenol angewandt. Bei der entsprechenden Synthese von Coniferylalkohol (23) aus Eugenol entstehen bei der Reduktion der Bromepoxide 19 neben 88% trans- auch 12% cis-Verbindung 24.

Notes: The Synthesis of 2,6:3,4-Dianhydro-1-deoxy-D-talo-hept-1-enitol, an Irreversible Inhibitor of β-Galactosidase from E. coliStarting from known 3,4,5,7-tetra-O-acetyl-2,6-anhydro-D-glycero-L-manno -heptononitril 2,6:3,4-dianhydro-1-deoxy-D-talo-hept-1-enitol (1) was prepared by a conventional multistep synthesis. The product 1 is supposed to react as an alkylating agent with a nucleophilic group at the glycon binding site of β-galactosidase from E. coli. In preliminary experiments 1 irreversibly inhibits the enzyme.

Notes: Der Mechanismus der thermischen Umlagerung von Alkyl-(silylmethyl)-ethern 1 → 2 wurde mit Hilfe von Kreuzungs- und Radikalabfangversuchen. Lösungsmitteleinflüssen. Substituenteneffekten und ESR-Studien untersucht. Dabei zeigt sich, daß eine Homolyse unter anchimerer Beteiligung der Silylgruppe wahrscheinlich ist. Die Wanderung des Silylrestes zum Sauerstoff leitet die Reaktion ein, wobei die starke Si—O-Bindung und resonanzstabilisierte Ketyl- und Alkylradikale gebildet werden. Vergleiche mit den wenigen, in der Literatur bislang bekannten Beispielen für anchimere Effekte bei unimolekularen Homolysen werden angestellt.

Notes: Aus den 1H-NMR-Spektren von spezifisch mehrfach deuterierten n-Butyl-Derivaten werden alle chemischen Verschiebungen und Kopplungskonstanten ermittelt. Die vicinalen Kopplungskonstanten hängen in nicht alternierender Weise von der Elektronegativität des Substituenten von seiner Entfernung vom koppelnden H—C—C—H-Fragment und der Konformation ab. Das Konformationsgleichgewicht um die mittlere CC-Bindung der n-Butyl-Verbindungen wird mit dem um die beiden mittleren CC-Bindungen der n-Pentyl-Derivate verglichen.

Notes: N1-Chlorhydantoine 3 bzw. 4 und Methyl-alkyl-sulfide 5 reagieren in Chloroform bei -25°C zu N-Sulfoniumchloriden 6. Bei der Einwirkung von tertiären Aminen auf 6 erhält man erst oberhalb von 0° C eine Stevens-Umlagerung zu den instabilen Imidaten 16, die beim Erwärmen in die isomeren Verbindungen 19 übergehen. Die langsame Umlagerung von 6 wird auf die Bildung des Anions 8 zurückgeführt. Durch Alkylierung von 8 entstehen N-Sulfoniumsalze 10, die mit tertiären Aminen spezifisch in die Imidate 12 umgelagert werden können.

Notes: Synthese und Eigenschaften neuer nichtcyclischer. Neutralliganden vom Kronenethertyp werden beschrieben. Charakteristische Strukturmerkmale sind zentrale Pyridin-Einheiten sowie starre donorfähige Endgruppen. Die Kronenether-Eigenschaften ergeben sich aus der Fähigkeit der Liganden, stöchiometrische, kristalline Komplexe mit Alkali-, Erdalkali- und Schwermetall-Kationen zu bilden: einige davon enthalten Wasser in stöchiometrischen Anteilen. NMR-Spektren zeigen, daß im gelösten Komplex helikale Ligandkonformationen vorliegen. Die Temperaturabhängigkeit der NMR-Spektren wird durch Dissoziations-Rekombinations-Gleichgewichte bzw. Konformationsänderungen der Komplexe gedeutet.

Notes: Die Struktur des 3,3,3,3,6,6,6,6-Octamethyl-4,4′-bi(1-thiacycloheptyliden)-5,5′-dions (3) wurde röntgenkristallographisch bestimmt. Die Verbindung kristallisiert in der Raumgruppe Pbca mit den Gitterkonstanten a = 17.59, b = 19.29, c = 12.10 Å. Z = 8. Das 2-Buten-1,4-dionsystem ist stark gespannt. Die beiden Carbonylgruppen stehen nahezu senkrecht auf der verdrillten zentralen Doppelbindung.

Notes: Propiolsäure-methylester vereinigt sich mit dem 1,3-Dithiolylium-4-olat 1a in 2,5-Stellung unter COS-Abspaltung regiospezifisch zum Thiophencarbonester 2a. Die Cycloadditionen an das Isomerenpaar 1b, c liefern dagegen Gemische aus den stellungsisomeren Thiophen-Derivaten 3a, b im 81:19- bzw. 30:70-Verhältnis. Auch die Reaktionen der mesoionischen Dithiolone 1d-h mit Propiolsäureester ergeben die a/b-Gemische 4-7. An Phenylacetylen, Acetylphenyl-acetylen. Phenylpropiolsäure-ethylester. Propargylalkohol und Tetrolsäure-methylester cycloaddieren 1b bzw. 1c unter Bildung der isomeren Thiophen-Derivate 8a, b-12a,b in 52-95proz. Ausbeute. Die beobachteten Regioselektivitäten werden qualitativ mit Hilfe der MO-Störungstheorie diskutiert.

Notes: Die durch elektronegative Substituenten R1-R4 stabilisierten Cyclopentadienyl-Anionen 1-4 reagieren mit den (Diacetoxyiodo)benzolen 5-12 bzw. mit 2-(Diacetoxyiodo)vinylchlorid (16) zu den Iodonium-Yliden 13 bzw. 17-19. Das im Vergleich zu 1-4 schwächer nucleophile Tetracyancyclopentadienyl-Anion (14) reagiert in Gegenwart von Mineralsäuren in gleicher Weise. Die 1H-NMR- und 13C-NMR-Spektren der Ylide werden angegeben.