bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oogenesis in the annelid Enchytraeus albidus with special reference to the origin and cytochemistry of yolk
Authors: Dumont James N. 
Published: February 2005

AbstractIn the annelid Enchytraeus albidus the ovary is composed of packets containing eight synchronously developing oocytes. Each oocyte in the packet is connected, via a bridge, to a common cytoplasmic mass. Developmental synchrony of oocytes within individual packets is probably related to the ooplasmic continuity.The young previtellogenic oocyte contains many polysomes, a few cisternae of smooth and rough endoplasmic reticulum, small Golgi complexes, and mitochondria. Many of the mitochondria are dumbbell‐shaped and may thus represent division stages.Vitellogenesis is marked by the appearance of peripherally located lipid yolk and small, densely staining granules scattered throughout the ooplasm. There is an increase of smooth endoplasmic reticulum, mitochondria, and enlarged Golgi elements. Small multivesicular‐like bodies, the early stages of developing yolk, are derived from the Golgi complex. The mature yolk sphere is bipartite and consists of (a) a variable number of dense spheres, the core bodies, which are produced in the ooplasm by the Golgi complex and which become embedded in (b) a dense matrix. The electron opaque tracer, horseradish peroxidase is incorporated into the oocyte and deposited in the matrix suggesting that this component of the yolk sphere is obtained by micropinocytosis. Enzyme digestions and various cytochemical techniques suggest that the core bodies are rich in carbohydrate, probably as glyco‐ or mucoproteins, and that the matrix is rich in lipid.
The influence of the nerve on lower jaw regeneration in the adult newt, Triturus viridescens,
Authors: Finch Robert A. 
Published: February 2005

AbstractThe present investigation was undertaken in an attempt to determine the role played by the nerve in the regeneration of the lower jaw of the adult newt, Triturus viridescens. The results indicated that the number of nerve fibers normally available at the amputation surface was very low compared with that of the newt forelimb. Furthermore, denervation of the lower jaw reduced the number of nerve fibers available to an extremely low level and maintained the number at a low level for up to four weeks without intervening redenervations. The regenerative events in the denervated and amputated lower jaws were indistinguishable histologically from those in amputated jaws having normal innervation. This presented an apparent exception to the general rule that regeneration of external body parts is dependent on the nerve. Several possible explanations are proposed by which this apparent exception might be explained. The process following amputation might be an exaggerated form of wound healing and tissue regeneration which can occur in the absence of nerves. The tissues of the lower jaw might be more sensitive to the influence of those nerve fibers present. The nerve fibers themselves might be qualitatively different and thus exert a greater influence on the tissues.
Gustatory sense organs in the food canal of aphids
Authors: Wensler Rita J. , Filshie Barry K. 
Published: February 2005

AbstractA sensory structure in the anterior region of the food canal of two species of aphid has been examined by light and electron microscopy. The dorsal wall is innervated by a total of 60 neurones which terminate, in groups, at 14 porous papillae on the cuticle. Paired papillae have also been detected in the ventral wall of this region. The fine structure of individual neurones and their grouping around papillae indicates a chemosensory function.The examination of moulting aphids shows that the distal portions of dendrites are shed with the exuviae.
Structure of the integument of a fresh‐water teleost, Bagarius bagarius (Ham.) (Sisoridae, pisces)
Authors: Mittal A. K. , Munshi J. S. Datta 
Published: February 2005

AbstractThe skin of Bagarius bagarius (Ham.) is devoid of scales but is rough due to the presence of numerous pentagonal epidermal elevations, which are separated by deep furrows at regular intervals. These elevated pentagonal regions of the epidermis are covered by dead cornified cells in the form of caps. As the old cap goes off a new one is formed by the death of the underlying epidermal cells. The middle layer of the epidermis is mainly composed of well defined polygonal cells. Their cytoplasm is granular in nature and give reactions for protein bound sulphydryl groups. The stratum germinativum is composed of two types of basal cells, the columnar cells and the spherical cells.The flask shaped mucous glands are restricted to the epidermal furrows and secrete either neutral or acidic mucopolysaccharides. Certain large specialysed granular cells are found in the epidermis which are grouped around the taste buds. These specialysed cells may be the photocytes.Two layers of the dermis can be distinguished—the relatively thin stratum laxum and the thick stratum compactum. Dermal papillae mainly support the taste buds. The pigment cells are arranged in two layers in the dermis.The subcutis is composed of loose connective tissues, richly infiltrated with the fat cells, nerves and blood capillaries.
Post emergence maturation of the eye of the adult black carpet beetle, Attagenus megatoma (Fab.): An electron microscope study
Authors: Butler Linda , Roppel Richard , Zeigler Joseph 
Published: February 2005

AbstractThe black carpet beetle, Attagenus megatoma (Fab.), has been reported to exhibit negative phototaxis immediately after emergence. In later adult life, after the period during which most oviposition has occurred, the beetles are found to be photopositive. The compound eyes of one‐day‐old (Post‐emergence) and nine‐day‐old (Post‐ovipositional) female beetles were studied by electron microscopy and a number of strong differences were found between eyes at the two ages. The corneal facets of one‐day eyes had the form of convex‐concave lenses, while those of nine‐day beetles were double‐convex lenses. The primary and secondary pigment cells of young eyes were large and contained much endoplasmic reticulum and little accessory pigment. In the older eyes the pigment cells were reduced and contained much pigment, the proportion of endoplasmic reticulum being greatly reduced by comparison with the one‐day eye. The cross‐sectional area of the rhabdom was greater in the older eye.The possible relationships between age‐related changes in eye morphology and behavioral changes during the same period are discussed.
Egg transport in lizards
Authors: Cuellar Orlando 
Published: February 2005

AbstractThe reproductive tracts of several species of lizards were examined to understand the events assoclated with the transport of discharged oocytes following ovulation. At the onset of the reproductive cycle the regressed ovaries and oviducts appear as inconspicuous structures pressed against the dorsal body wall. As the reproductive cycle progresses, they undergo marked changes in position and size. The oviducts migrate ventrally and surround the growing ovarian oocytes, which move anteriorly where coelomic space is more abundant and eventually press intimately against the infundibulum. When ovulation occurs the ostium is in a remarkably strategic location for directly receiving the ovulated oocytes. The virtual isolation of the ovaries from the general coelom by the encapsulating oviducts, and the intimate association of the pre‐ovulatory oocytes with the infundibular ostium do not support the current concept advocating the migration of loose ova following ovulation. An alternative explanation for the “trans‐coelomic migratiion of ova” is proposed.
Functional morphology of the digestive tract epithelium in Phoronis vancouverensis (Pixell): An ultrastructural and histochemical study
Authors: Vandermeulen John H. 
Published: February 2005

AbstractThe ultrastructure of the gut regions of the marine filter‐feeder Phoronis vancouverensis was correlated with enzyme activity as revealed histochemically. The oesophagus, proventriculus, and stomach epithlia showed intense esterase and acid and alkaline phosphatase activity. The staining reaction was confined primarily to small globules in the apical cytoplasm of the epithlial cells. Electron micrographs of the same regions showed a high incidence of zymogenlike granules, with a corresponding abundance of ribosomes and of rough endoplasmic reticulum. Also, the proventricular and to a lesser extent the stomach epithelia were found to contain a large number of lipid bodies. This was confirmed with positive Sudan IV staining for fats.The intestinal region of the gut was found devoid of esterase and phosphatase activity. The epithelial surface in this region was found elaborated into microvilli. The entire gut is ci iated. A new paired‐cilium apparatus is described in this phylum.From these findings Phoronis vancouverensis is concluded to be suitably adapted to its continuous filter‐feeding existence, with the anterior gut epithelia synthesizing hydrolytic enzymes for release into the lumina of the proventriculus and stomach. Subsequently, in the hindgut the products of initial extra‐cellular digestion are absorbed via the microvilli and treated intracellularly within the intestinal epithelium. The proventriculus is further thought to function in lipid absorption and storage. The presence of chromaffin‐like granules observed in some proventricular and intestinal epithelial cells suggests that digestion in this phylum may in part be under neurosecretory control.
Microscopic anatomy of the cardiac ganglion of Limulus polyphemus
Authors: Bursey Charles R. , Pax Ralph A. 
Published: February 2005

AbstractThe morphology of the cardiac ganglion of Limulus polyphemus (L) was examined by reconstructions from stained serial sections. This ganglion is composed of two distinct parts: a fiber tract extending the entire length of the heart and a cellular portion underlying the fiber tract. The cellular portion extends continuously from the third pair of ostia to the posterior terminus of the heart. The mean number of ganglion cell bodies is 231. Most of the ganglion cells are located among the glial elements of the cellular portion. The greatest density of cells is found in segments 5 and 6. Six cell types are recognized: (1) large pigmented unipolar cells approximately 120 μ in diameter with distinct connective tissue capsules around them; (2) large pigmented bipolar cells approximately 120 μ in length which are also encapsulated; (3) pigmented multipolar cells approximately 80 μ in diameter which are free of capsules; (4) small pigmented bipolar cells approximately 40 μ in length which are encapsulated but which are found exclusively within the fiber tract; (5) non‐pigmented multipolar cells approximately 30 μ in diameter which are found scattered among the connective tissue elements of the cellular portion; and (6) small non‐pigmented cells approximately 10 μ in diameter which are found within the unipolar cell capsule and scattered among the connective tissue elements of the ganglion.The variability in cell numbers and the random location of cells points toward non‐specific anatomical connectivity between elements of this ganglion.
Histogenesis of Swiss white mouse secondary palate from nine and one‐half days to fifteen and one‐half days In utero. I. Epithelial‐mesenchymal relationships—light and electron microscopy
Authors: Sweney L. R. , Shapiro B. L. 
Published: February 2005

AbstractDevelopment of the secondary palate in Swiss white mouse embroyos was studied from age nine‐and‐one‐half days in utero to the stage of mesenchymal coalescence in the secondary palate (approximately fifteen‐and‐one‐half days). The greatest changes observed occur in the mesenchyme. At early stages, mesenchymal cells underlying oral ectoderm of the head are few and only occasionally contact the ectoderm. Electron micrographs show large intercellular spaces between the ectodermal cells. As embryogenesis continues, the mesenchymal cells become more numerous, closer to each other and closer to the epithelium. Just prior to horizontal transposition of shelves, the mesenchymal cells spread farther from each other and from the palatal epithelium and epithelium of the palatal tip becomes stretched. Ultrastructurally the intercellular spaces between epithelial cells of the palate tip have become much smaller. Some mitochondria in some epithelial cells are swollen and have clear matrices and distorted cristae. The shelves become horizontal and meet in the midpalate. Cells with degeneration bodies are seen in the epithelial seam. The seam undergoes autolysis and is replaced by mesenchyme. The morphological changes described, particularly in the mesenchyme, may play an important role in determining the effect of various teratogens at different stages of palatal development. The changes in both mesenchyme and epithelial cells in the later stages may constitute part of the process of preparing shelves for fusion as postulated by Pourtois ('66).
The body wall of cheilostome bryozoa. III. The frontal wall of Watersipora arcuata banta, with a revision of the cryptocystidea
Authors: Banta William C. 
Published: February 2005

Abstract(1) The frontal wall of the encrusting cheilostome, Watersipora arcuata is a one‐layered, evenly perforated calcareous shield which subdivides the metacoel into two compartments, the perigastric coelom and the hypostega. These compartments communicate through four and six “intrazoidal septulae” at the corners of the frontal wall. (2) The frontal wall develops by apposition independently of the ectocystal epitheca. The ascus develops as an invagination of the epitheca. These observations are consistent only with the view that the frontal wall of this species is a cryptocyst. (3) The terms “tremocyst,” “olocyst,” and “pleurocyst” are poorly understood and ambiguously defined; they should not be used until more information is available. (4) The taxa Anasca, Ascophora, Ascophora Imperfecta, and Ascophora Vera are polyphyletic and should ge dropped and replaced by Silén's (1942) more natural taxa. Silén's Cryptocystidea should be enlarged to include Watersipora and related ascusbearing cheilostomes.
Observations on the pineal system in the hamster. I. Relations of the superficial and deep pineal to the epithalamus
Authors: Sheridan Michael N. , Reiter Russel J. 
Published: February 2005

AbstractA mass of pineal tissue has been observed associated with the habenular commissure and the apex of the pineal recess in the golden hamster. Previously, it had been thought that all of the pineal system in the hamster was located at the confluence of sinuses just beneath the skull. To distinguish the two components of the pineal system, that in the dural position is called the superficial pineal and the mass associated with the habenular commissure is called the deep pineal.
Observations on the pineal system in the hamster. II. Fine structure of the deep pineal
Authors: Sheridan Michael N. , Reiter Russel J. 
Published: February 2005

AbstractThe fine structure of the deep pineal, a mass of pineal parenchyma positioned in the roof of and caudal to the pineal recess is described. The fine structure of deep pineal is similar to earlier descriptions of superficial pineal.The parenchymal cell displays abundant mitochondria, many of which contain a tubular internal structure, a prominent Golgi apparatus, and smooth and granular endoplasmic reticulum.The parenchymal cells are extensively branched and terminate in club‐like endings. Pineal cell process terminations contain a profusion of vesicles of varying size, many of which contain an electron‐dense granule. The granules are presumed to be associated with the secretory product of the parenchymal cell.The deep, unlike the superficial, pineal contains a relatively high concentration of glial cells and processes, some of which contain mitochondria with a unique internal structure.
Salivary glands of heteromyid rodents, with a summary of the literature on rodent submandibular gland morphology
Authors: Flon Helen , Gerstner Robert , Mitchell Ormond G. , Feldman Audrey 
Published: February 2005

AbstractThe principal parenchymal elements of the submandibular glands of the heteromyid rodents Dipodomys merriami, Perognathus longimembris, Perognathus fallax, Perognathus penicillatus and Perognathus baileyi consist of acini, granular tubules and striated ducts.Acinar cells of the four species of Perognathus are aniline blue, PAS (magenta) and Alcian blue (pH 2.5) positive and metachromatic with toluidine blue and safranin. The granules of the tubule cells are orthochromatic and react with aniline blue, orange G, the PAS reagent (deep pink) and the tryptophan indicator, xanthydrol. Acinar and tubule cells of D. merriami exhibit similar reactions except for the Alcian blue stain. Acinar cells of D. merriami do not react with Alcian blue.Submandibular glands of D. merriami exhibit a sexual dimorphism of the granular tubules. There is little observable difference between the sexes in the species of Perognathus but the ratio of granular tubules to acinar elements, the degree of hypertrophy of the tubules, and the amount of mucosubstance and protein (granules) contained in their cells are different in the four species studied.Since these desert rodents have similar habitats and habits, the differences observed between the two heteromyid subfamilies studied, as well as among the four members of a single subfamily, suggest that these are inherent species variations rather than variations of adaptation to environment.
Morphology of ovarian changes in the garden lizard, Calotes versicolor
Authors: Varma Santosh Kumari 
Published: February 2005

AbstractOvarian changes during the reproductive cycle of the oviparous garden lizard (Calotes versicolor) are described. It ovulates from last week of June to first week of September but most often in July and August when the monsoon occurs. The number of eggs ovulated vary from 10 to 32. After ovulation, the ovaries are reduced in size. From October to May, the ovaries contain small pre‐vitellogenic follicles, which increase in size in June when most of yolk deposition occurs. Several nuclei are seen in the ooplasm of pre‐vitellogenic follicles; they are finally absorbed before yolk deposition starts. Follicular atresia generally occurs in follicles with polymorphic granulosae, in post‐ovulatory ovaries. Presumably interstitial gland cells are formed by the hypertrophy of the theca interna cells of atretic follicles. Pre‐ovulatory follicles have highly vascularized thecae and invaginations of the follicular epithelium. After ovulation, the follicle cells hypertrophy to form the luteal cell mass filling the follicular cavity. Fibroblasts, which appear to arise from the theca interna, invade the luteal cell mass and form septa. Capillaries occur in the luteal cell mass.
The ultrastructure of the pygidial defence glands of the carabid Pterostichus madidus F
Authors: Forsyth D. J. 
Published: February 2005

AbstractPygidial defence glands, which are universal in Caraboidea, are paired, cuticular invaginations of the body wall.In Pterostichus madidus F. the glands contain a nauseous, corrosive secretion that can be discharged forcibly to deter attack by predators. The cells producing the secretion are of one type only. Electronmicroscopy shows that the ducts which drain these cells are not intracellular but are separated from the cell contents by a plasma membrane. The cuticular walls of the duct appear to effectively screen the cell from the disruptive effect of its final products of secretion. The duct‐carrying epidermal cells which are modifications of the epidermis covering the rest of the gland support the ducts from the secretory vesicles to their entry into the central lumen of each secretory lobe. There is a single duct‐carrying cell around each duct.
The biology of cartilage. II. Invertebrate cartilages: Squid head cartilage
Authors: Philpott Delbert E. , Person Philip 
Published: February 2005

AbstractIn both light and electron microscopes, head cartilage from the squid Loligo pealii strongly resembles vertebrate hyaline cartilage. The tissue is characterized by the presence of irregularly‐shaped cells suspended in an abundant matrix. Cell and matrix contents stain metachromatically with cationic dyes such as toluidin blue. Each cell gives off extensions which ramify via a network of channels throughout the matrix. Thereby, a system of inter‐connecting canaliculi is established, with many similarities to the intercanalicular systems seen in vertebrate bone and cartilage tissues. In the electron microscope, the squid cartilage cells are seen to have very abundant endoplasmic reticulum and Golgi complex material. Mitochondrial transformations involving loss of cristae, the appearance of filaments in the mitochondrial matrix, and figures suggesting budding, also occur. Nuclear pores are numerous and easily detected. The matrix is characterized by the presence of a system of decussating fibrils which form polygonal figures, with granules usually evident at the points of intersection of fibrils. By chemical analysis the tissue contains 3‐ and 4‐hydroxyproline and hydroxylysine. Preliminary wide single x‐ray diffractions show a pattern characteristic for unoriented collagens, with 12 Å (intermolecular) and 2.86 Å (helix) reflections.
Fine structure of spermatogonia and intercellular bridges in Macaca nemestrina
Authors: Gondos Bernard , Zemjanis Raimunts 
Published: February 2005

AbstractSpermatogonia of the monkey, Macaca nemestrina, were studied with the electron microscope. The spermatogonial nucleus is characterized by dense homogeneous chromatin and an eccentric nucleolus with a prominent surrounding clear zone. Cytoplasm consists chiefly of free ribosomes and vesicular endoplasmic reticulum. Scattered mitochondria with closely spaced transverse cristae are arranged singly and in pairs separated by thin electron‐dense bands. Binucleated spermatogonia resemble other spermatogonia in their ultrastructural characteristics, but contain an increased number of lysosome‐like structures and degenerating mitochondria.Spermatogonial interconnections are of two types: broad cytoplasmic connections and narrow intercellular bridges. Connected cells are always identical in appearance and stage of maturation. Multiple connections occur. Interconnection of spermatogonia provides a syncytial type of arrangement which allows synchronization of differentiation and results in similar apperance of adjoining cells. Similarity of regressive changes in adjacent degenerating cells is explained by the presence of intercellular bridges.
Sense organs of a thysanuran, Ctenolepisma lineata pilifera, with special reference to those on the antennal flagellum (Thysanura, Lepismatidae)
Authors: Slifer Eleanor H. , Skkhon Sant S. 
Published: February 2005

AbstractSix types of sense organs are present on the antennal flagellum of Ctenolepisma lineata pilifera: tactile hairs, trichobothria, thick‐walled chemoreceptors, small thin‐walled chemoreceptors and coeloconic chemoreceptors. The number, size and distribution on the antenna of each type have been recorded. The base of the tactile hair is more complex than is that of other insects examined earlier. Trichobothria, long, slender hairs that oscillate in a gentle puff of air, are an unusal feature in insects and especially so for the antenna. The two types of thin‐walled chemoreceptors differ in shape, size and in the structure of their walls and internal parts. A pocket‐like depression of the floor of the cavity in which the peg of the coeloconic sense organ is set has not been found in earlier studies. Its function is unknown.The axons from the sensory neurons extend along the inner surface of the antennal epidermis as a sheet of fibers lining the antennal lumen. Near the pedicel the axons leave the epidermis and join to form the antennal nerve.A few observations on sense organs on appendages other than the antennae and some notes on behavior are included.