bluuebunny/crossref_metadata_2025_split huggingface dataset:
The anatomy of the parotoid gland in Bufonidae with some histochemical findings. I. Bufo marinus
Authors: Hostetler Jeptha R. , Cannon M. Samuel 
Published: February 2005

AbstractThe gross and microscopic anatomy of the venom producing parotoid glands of Bufo marinus has been studied by light and electron microscopy and reactions for the presence of glycoprotein and mucopolysaccharides, the catechollamines, 5‐hydroxytryptamine or dopamine, glucose‐6‐phosphatase, adenosine triphosphatase and the steroid nucleus and cholesterol and its esters have been performed. The gland is composed of numerous individual lobules, each lobule surrounded by a double cell layer. The interior surface of the outer layer is thrown into small cytoplasmic projections which traverse an intercellular space and interdigitate with microvilli formed by the outer plasmalemma of the inner layer. The outer layer resembles smooth muscle‐like cells, is rich in adenosine triphosphatase, contains many pinocytotic vesicles and various organelles and may function in some aspect of venom synthesis, active cellular transport and contraction in the discharge of the secretory product. The inner layer shows a positive chromaffin reaction, contains various organelles, appears devoid of a plasmalemma on its inner surface and is involved in venom formation and release via an apocrine type of secretion. The intercellular space is rich in PAS positive materials, while the secretory product, itself, demonstrates a positive chromaffin reaction. The significance of these findings is discussed.
The gastric mucosa of two monotremes: The Duck‐billed platypus and echidna
Authors: Krause William J. , Leeson C. Roland 
Published: February 2005

AbstractThe gastric mucosa of both the echidna and platypus is aglandular and the lining epithelium is stratified squamous. The latter exhibits three principle layers: stratum germinativum, stratum spinosum, and stratum corneum. The cytoplasm of cells composing the first two strata of both species shows bundles of tonofibrils and numerous free ribosomes. Cells of the stratum spinosum in the platypus also show numerous dense granules limited to the peripheral cytoplasm. The stratum spinosum of both species is comprised of fusiform‐shaped cells whose adjacent cell membranes show extensive interlocking. The stratum spinosum of the echidna in addition shows numerous intercellular bridges. Cells of the stratum corneum become flattened and elongate and in the echidna nuclei near the surface appear to degenerate. Cells comprising the stratum corneum of the platypus exhibit well preserved nuclei and contain scattered large granules of varying electron density. Prior to sloughing, cells near the surface of both species show a separation of adjacent cell membranes. True keratinization is not found in the gastric lining epithelium of either species and the epithelium lining of the stomach of the echidna more closely represents a form of parakeratosis. Delicate papillae containing capillaries extend considerable distances into the overlying epithelium of both species and are thought to contribute to its nutrition.
Development of ultraviolet‐reflecting butterfly scales: How to make an interference filter
Authors: Ghiradella Helen 
Published: February 2005

AbstractLight and electron microscope studies of development of the ultraviolet‐reflecting scales of male Colias eurytheme butterflies show that basic developmental processes are similar to those of other scales. The ridges form between bundles of microfilaments and as they form they buckle to produce the lamellae seen in the adult scales. There is evidence that the buckling may be purely in response to mechanical stress and that some of the bundles of microfilaments may produce such stresses.
Rostral pores in turtles
Authors: Winokur Robert M. , Legler John M. 
Published: February 2005

AbstractRostral pores are epidermal invaginations which occur on the internarial region of most chelonians. Representatives of all Recent chelonian families and 67 of the 74 extant genera were examined grossly and/or histologically. Pores are absent only in the families Carettochelyidae, Cheloniidae, and Dermochelyidae. The number and microscopic structure of pores vary markedly within and between taxa. Morphological data suggest that rostral pores could function in mechanoreception. The possible origin and evolution of rostral pores are discussed in the context of other chelonian integumentary speializations.
Filaments and microtubules in the gonadotrophic cell of the lizard, Anolis carolinensis
Authors: Forbes M. S. , Dent J. N. 
Published: February 2005

AbstractGonadotrophic cells in the pars distalis of Anolis carolinensis often contain juxtanuclear concentrations of filaments with diameters intermediate in size (approximately 100 Å) between microtubules and microfilaments. Their size and their substructure, which gives them a tubular appearance when they are displayed in cross‐section, appear to place these filaments in the “intermediate filament” category (Ishikawa et al., '68). In their juxtanuclear position in the intact animal, the intermediate filaments are collected in randomly‐oriented tangles. In castrated specimens of Anolis, gonadotrophs degranulate and elongate. During this elongation, increased numbers of microtubules appear in orientation parallel to the long axis of the cell, and the 100 Å filaments reassemble in rod‐like masses oriented parallel to the microtubules. This apparent distributional interaction may facilitate the elongation of the cell. Intimate physical associations between the intermediate filaments and secretory granules suggest that the filaments may act in the movement of the granules during the processes of degranulation and secretion.
Sense organs on the antennae of two species of thrips (Thysanoptera, insecta)
Authors: Slifer Eleanor H. , Sekhon Sant S. 
Published: February 2005

AbstractThe antennae of two species of thrips,Bagnalliella yuccae(Hinds) andFrankliniella tritici(Fitch), have been examined with the light and electron microscopes. The antennal flagellum of both species is provided with tactile hairs, thick‐walled chemoreceptors and thin‐walled chemoreceptors. In addition,B. yuccae, but notF. tritici, has a single coeloconic chemoreceptor on the dorsal surface of the pedicel. Observations were made on the fluids in the lumen of the antennae ofE. yuccaein the living insect. The movement of the fluids probably has an important physiological significance.
The hemocytes of an isopod Ligia exotica roux
Authors: Ravindranath M. H. 
Published: February 2005

AbstractThe morphological features of the hemocytes of the crustacean Ligia exotica are similar to hemocytes of insects and millipedes. Jones system of hemocyte classification is extended to crustacean hemocytes. As in insects, seven classes of hemocytes, identified as prohemocytes, plasmatocytes, granular hemocytes, cystocytes, oenocytoids, spherule cells and adipohemocytes, occur. The prohemocytes can be subdivided into five categories that probably represent the precursor of major cell types. The structural and chemical features of other major cell classes are distinct and support the concept of Jones ('62) that these types might have different lineages and might not be capable of transforming into one another. Some of the prohemocytes, plasmatocytes and granular hemocytes are amoeboid. Cystocytes do not bring about any visible plasma coagulation similar to their counterpart in millipedes. Oneocytoids and adipohemocytes are rare. Plasmatocytes, cystocytes and oenocytoids occur in conglomerates, the significance of which is discussed. The cell types are compared with those of the hemocytes of other crustaceans. It is suggested that the nomenclature based on morphological characters is more suited for crustacean hemocytes than a nomenclature based on behavioural and physiological characters.
Fine structure of nuchal organs in some errant polychaetous annelids
Authors: Whittle A. C. , Zahid Z. R. 
Published: February 2005

AbstractThe nuchal organs of polychaetes from four different families (Nereidae, Nephtyidae, Phyllodocidae and Glyceridae) were examined with the light and electron microscopes. In each case, the organ consists of ciliated cells and primary sensory elements. The ciliated cells are similar to the cells of the adjacent epidermis but bear motile cilia. Primary sensory neurons are situated within the organs in Nephtyidae and Phyllodocidae, but are located within the brain in Nereidae and Glyceridae. Each sensory cell gives rise to a distal process which penetrates between the ciliated cells to form an apical sensory bulb bearing modified cilia. Apically these processes are lined with juxtamembranous plaques. The ciliated cells are innervated by efferent axons from the brain, and in Nereis the axons appear to be peptidergic. The elements comprising the nuchal organs closely resemble those of the vertebrate olfactory mucosa.
Fine structure of the digestive tract epithelium in the terrestrial isopod. Armadillidium vulgare
Authors: Vernon G. M. , Herold Laura , Witkus E. R. 
Published: February 2005

AbstractAn ultrastructural study of the hindgut, associated hepatopancreatic lobes and hepatopancreatic ducts of the terrestrial isopod, Armadillidium vulgre was undertaken. The simple epithelium which lines the heptopancreas consists of two cell types, S and B. Both cell types have numerous microvilli. A simple epithelium consisting of one cell type lines the hepatopancreatic ducts and the hindgut. Microvilli are not evident in the duct. The cells of the duct and the hindgut are covered with a cuticle. Dense granular bodies are characteristic of the cytoplasm of the duct cells. The hindgut epithelial cells have pronounced apical and basal‐lateral cytoplasmic infoldings. Apical infoldings from large subcuticular spaces, especially in the posterior hindgut. Microtubules and large numbers of mitochondria are associated with the cytoplasmic infoldings. Large microtubular bundles are seen in the peripheral cytoplasm, and residual bodies are present in the central cytoplasm. Lateral plasma membranes form septate desmosomes in the apical region of cells, while zonulae adherentes and intercellular spaces are found basal to the septate desmosomes. The cellular organization of the hindgut is suggestive of cells active in water and ion transport.
A comparative histological study of mammalian bone
Authors: Singh I. J. , Tonna E. A. , Gandel C. P. 
Published: February 2005

AbstractThis report adds to the available information on comparative histology of mammalian bone and introduces a semi‐quantitative approach to its study. Bone samples consisted of large fragments of rib tibia and/or femur from humans, laboratory rodents and from animals that died at the Bronx Zoological Gardens. A total of 44 bone specimens representing six mammalian orders were available. Decalcified paraffin‐embedded 10 μm histological cross‐sections were examined at × 320. Qualitative observations were supplemented with measurements of the frequency and size distributions of Haversian and non‐Haversian canals. The relative distribution of lacunae was also ascertained. The standard textbook description of mammalian bone as consisting mainly of secondary osteons was not generally seen except in Primate (especially human) bone. Rats showed a few scattered osteon‐like structures, but bones of Marsupialia, Insectivora, Artiodactyla and Carnivora were entirely devoid of them. Generally, vascular bone with longitudinal canals was seen except in Lorisidae which showed a reticular type of bone. The distribution of primary longitudinal canals and the number of “filled” or “apparently empty” lacunae/unit area of bone varied both inter‐species and among different areas in the same bone. Large areas of acellular and non‐vascular bone were encountered in all specimens. This preliminary study revealed that species differences i bone microstructure involve the relative distribution of the same basic components which lend themselves to quantitative treatment. Comparative investigations of bone histology at many ontogenetic and phylogenetic levels should yield significant quantitative information in bone biology.
Some anatomical aspects of the cardiovascular system of antarctic seals and their possible functional significance in diving
Authors: Drabek Charles M. 
Published: February 2005

AbstractThe hearts and ascending aortae of 11 Weddell seals, Leptonychotes weddelli, three adult Crabeater seals, Lobodon carcinophagus, two adult Ross seals, Ommatophoca rossi, and one adult Leopard seal, Hydrurga leptonyx, were examined for comparison with terrestrial forms. The Weddell seal specimens were from animals ranging in age from midterm in fetal development to mature adults. All specimens were collected in 1971, 1972, and 1973, from McMurdo Sound and the Ross Sea, Antarctica.The phocid hearts were characteristically broader and flatter than those of other carnivore families and they tended toward bifid apices. The heart form indices (height/circumference) averaged 31.5 compared to 39.0 for felids. The right ventricular chambers of the Antarctic seals were found to average longer in Weddells and narrower in all, than those reported for four other carnivore families. An elastic enlargement was present in the ascending aortae of all seals. The largest diameter of the aortic bulb averaged 25.5 mm more than the base of the aorta in the adult Weddell seals which represented an increase of 72.5% over the base.It is suggested that the general heart form, and especially the ascending aortae, are anatomical adaptations to diving. The compressed heart makes possible unimpaired function when the chest is compressed during deep dives. The aortic bulb maintains mean arterial blood pressure and perfusion of the brain and cardiac tissue during diving bradycardia.
Cytochemical observations of larval development in Eunapius fragilis (Leidy): Porifera; spongillidae
Authors: Harrison Frederick W. , Cowden Ronald R. 
Published: February 2005

AbstractFreshwater sponges of the family Spongillidae reproduce sexually through formation of a parenchymula larva. The cytochemical characteristics of parenchymula larval metamorphosis — beginning with the blastula and terminating with the motile escape stage — for the spongillid Eunapius fragilis (Leidy) have been defined using both absorption and fluorescent cytochemical methods, particularly those demonstrating protein end‐groups. Morphogenesis of the parenchymula larva of E. fragilis involves the interrelated processes of cytodifferentiation and mobilization of reserve materials. Larval development has been categorized into five stages, from blastula (stage I) through the escape stage (stage V). Parenchymula development is characterized by morphogenetic precocity, a fact influencing the rate of mobilization of cytoplasmic reserves, cytodifferentiation, and the fate of individual cell types. With attainment of the stage V parenchymula, the larva is, essentially, a mobile adult sponge exhibiting flagellated chambers, canal systems, a well defined connective tissue stroma, a diverse cell population consisting of specialized elements and a totipotent archeocyte reserve, and a terminal epitheliocyte line. The present study recognizes differences in development within the spongillids as well as within more remote poriferan taxa — emphasizing the need for detiled understanding of particular processes in individual species before proposing major generalizations about development in this ancient but evolutionally specialized group.
Fine structure of an elongated dorso‐ventrally compressed echinoderm (holothuroidea) spermatozoon
Authors: Atwood David G. 
Published: February 2005

AbstractThe spermatozoon of Cucumaria pseudocurata is unique among those of the echinoderms in that it is tabloid in shape, i.e., elongated and dorsoventrally compressed. The sperm consists of a dorsal surface which contains an extensive striated rootlet‐like structure located within a dorsal groove and a ventral surface which contains a medially situated acrosome. A single mitochondrion lies at the base of the nucleus. The flagellum is unusual in that a 9 + 3 tubular arrangement is observed in the mid‐tail region.The acrosome consists of an acrosomal granule bounded by a limiting membrane and a surrounding periacrosomal layer. The granule is irregular in shape with the anterior‐posterior surfaces flaring out, forming pockets in the periacrosomal material. The ventral granule surface bulges forming a close association with the plasma membrane. The dorsal surface is indented. Ventral to the depression (within the granule) is a small area containing a particulate‐fibrous material. To the inside of the granule limiting membrane there is a second membrane‐like structure (incomplete) which extends from the anterior‐posterior surfaces around the dorsal face of the granule. Dorso‐medial to the granule the periacrosomal layer contains a particulate‐fibrous region lodged within the granule depression. This material is presumably the precursor of the acrosomal filament.Prominent cytoplasmic folds extend off from the basal flagellar region. The proximal and distal centrioles are situated perpendicular to one another within the mitochondrion. Centriolar satellite materials are associated with both centrioles. Toward the base of the tail the satellite of the distal centriole consists of nine radiating arms extending at an angle of 45° to the axis of the centriole. Each arm terminates in a dense thickening. The striated rootlet extends anteriorly from the distal centriole to just below the level of the acrosome.
The form and function of retractile claws in the felidae and other representative carnivorans
Authors: Gonyea W. , Ashworth R. 
Published: February 2005

AbstractRecent behavioral studies have shown the primary organ of prehension used in capturing prey to be the claw equipped forelimbs. In light of its functional importance, the claw retractile mechanism for 15 felid species is described and its function studied. The anatomy of the claw retractile mechanism for felids is then compared to that of other carnivorans.For felids, claw retraction is mechanically possible due to the unique shape of the middle and distal phalanges. Claw retraction, however, is a function of the dorsal elastic ligaments and not of the forearm extensor muscles. The resistance provided by these ligaments allows for flexion of the wrist and digital joints without claw protrusion. Moreover, co‐contraction of both forearm flexor and extensor muscles is necessary to produce claw protrusion.The functional anatomy of claw retraction for felids differs considerably from that of most other carnivorans. However, the claw retractile mechanism for some advanced viverrids is structurally similar to that of the felids. For these viverrids prey seizing, as in the felids, has become a function of the forelimbs. For the other families of carnivorans, the jaws and not the forelimbs are used as the primary organ of prehension and the anatomy of the claw retractile mechanism reflects functional demands placed on it other than grasping and holding prey.
Neurosecretory system of the American dog tick, Dermacentor variabilis (Acari: Ixodidae). II. Distribution of secretory cell types, axonal pathways and putative neurohemal‐neuroendocrine associations; comparative histological and anatomical implications
Authors: Obenchain Frederick D. , Oliver James H. 
Published: February 2005

AbstractHistological observations using specialized techniques reveal neurosecretory cells in 18 centers throughout the rind (cortex) of the central nerve mass or synganglion of Dermacentor variabilis. Many cells contribute to complicated networks of neurosecretory pathways and tracts in pre‐ and post‐esophageal portions of the synganglion. The four types of neurohemal‐neuroendocrine associations found in Dermacentor resemble structures found in soft ticks (Argasidae) and in other Arachnida, but are more diverse than those described from any other single species. Neurosecretory terminals are distributed diffusely and in two concentrated associations within the perineurium of the synganglion and major peripheral nerves. Terminals are also distributed in the perineurial layers of lateral segmental organs which lie in the general hemocoel at the level of the pedal nerves. A retrocerebral organ complex surrounds the esophagus at its junction with the midgut. The complex includes dorsal and ventro‐lateral lobes (containing neurosecretory terminals and intrinsic secretory cells) and the proventricular (neurohemal) plexus. This plexus seems to be a modified (concentrated) cardioglial association. Cardioglial associations are also formed by the neurosecretory innervation of vascular walls of the dorsal aorta and circulatory sinuses which envelope the synganglion and major peripheral nerves. Inferential considerations of neurosecretory and endocrine interactions in the Acari are based on these anatomical and histological data which also provide the basis for evolutionary considerations of anatomical relationships and specializations in the neurosecretory systems of other Arachnida.
Structure development and evolution of the male pheromone system in some noctuidae (Lepidoptera)
Authors: Clearwater J. R. 
Published: February 2005

AbstractPheromone systems from seven species of noctuid are examined. Much of the structure of scales from the wings and/or the abdomen is interpreted as a modification for secretion or release of a pheromone. Scales with an extremely complex surface provide a large evaporation surface, while those connected to secretory cells show less superficial folding than body‐covering scales.The development of the secretory gland and diseminatory scales in Mamestra configurata is followed from the exuvial pharate adult stage to emergence. Both components are paired and develop from epidermal cells lining a pair of large lateral invaginations. They may have resulted through division of a group of less specialized cells that originally combined the function of pheromone production and release.
Muscle activity in rat locomotion: Movement analysis and electromyography of the flexors and extensors of the elbow
Authors: Cohen Avis H. , Gans Carl 
Published: February 2005

AbstractFootfall patterns and time sequence of activity are described for white rats conditioned to run freely in an activity wheel (which they drive). Motion is described in terms of soft contact, hard contact, soft contact, and flip phases. Duration of stride decreases and length of stride increases from walk to trot to canter to gallop. Myographic analysis shows that the brachialis has a major tonic function after it fires strongly during the flip phase and during much of the hard contact phase. Animals running at canter or gallop show major asymmetries between forelimb muscles on the first paw and on the lead paw sides.