bluuebunny/crossref_metadata_2025_split huggingface dataset:
The microscopic anatomy of epidermal glands in two species of gekkonine lizards, with some observations on testicular activity
Authors: Chiu K. W. , Maderson P. F. A. 
Published: February 2005

AbstractThe gross and microscopic anatomy of epidermal glands has been studied in laboratory maintained tokays (Gekko gecko), and house geckos (Hemidactylus bowringii) captured from the wild throughout the year. Annual testicular activity in the house gecko has also been studied. While no significant differences in glandular development at various times have been observed in G. gecko, there are clear‐cut annual cycle in H. bowringii. The evolution of epidermal glands in gekkonid lizards is reviewed; the cellular dynamics of β‐glands are compared with those of unspecialized epidermis; the possibility that gekkonine epidermal glands respond to quantitative variation in circulating testosterone titers is discussed.
Development of the head skeleton and pectoral girdle in Esox
Authors: Jollie Malcolm 
Published: February 2005

AbstractA consideration of head development in two species of Esox, lucius and americanus (ssp. vermiculatus) representing the two subgenera Esox and Kenozoa respectively, focused on the significance of the variations of the latero‐sensory canal system, its associated bones, and other skeletal elements. In living forms only aspects of “regression” or specialization can be studied. Canals tend to be reduced to pit lines first at their termini but can be broken in their course. Pit lines range from nearly canals to surface structures, or even fail to develop. The number of neuromasts varies. Canal bones develop from two centers: neuromast related and deeper membranous centers which may have no relationship to neuromasts. Tooth‐bearing and non‐canal‐related dermal bones have only membranous (original) centers. The number of neuromasts associated with a bone usually does not affect its development or form. In the case of the circumorbital bones, the extrascapulars, and the nasal, a one to one relationship has developed by regression – towards the development of the latero‐sensory component only. The idea that reductions in bone number are commonly traceable to fusion is rejected although examples of fusion are known. Most bones that disappear are simply lost (no blastema or other evidence of their presence seen in development). The relationship between dermal bone and chondral bone is examined and there is evidence of the former giving rise to the latter. The ontogenic order of appearances shows a feeding (functional) correlation.
Organization of the teleostean nucleus rotundus
Authors: Ito Hironobu , Kishida Reiji 
Published: February 2005

AbstractThe nucleus rotundus of 21 species of teleosts was studied by a modified Bodian and the Golgi method to clarify the histological organization, with special reference to the cell lamination and the glomerular formation.The common components of the nucleus in all species are as follows: a thick fiber bundle which comes from the commissura horizontalis and enters the nucleus from the dorsal surface, many small cells, large cells, glomeruli, and a surrounding fibrous capsule. The nuclei of all species studied are classified into three types mainly on the distribution of the small cells, and to a lesser degree on the location of the large cells and the glomeruli.The first type of nucleus has small cells. large cells and glomeruli throughout its extent. In the second type of nucleus, many small cells form a peripheral cell layer, while the large cells and glomeruli are found all over the nucleus.The third type of nucleus is clearly laminated. It is composed of four layers arranged concentrically around a central fiber net in the following order: a glomerular layer, a fibrous layer, a small‐cell layer, and a peripheral fibrous capsule. In some species, the large cells are located in the fibrous capsule, and all glomeruli contain a star‐like structure, which corresponds to the tips of the large cell dendrites.
The anatomy of the parotoid gland in Bufonidae with some histochemical findings II. Bufo alvarius
Authors: Cannon M. Samuel , Hostetler Jeptha R. 
Published: February 2005

AbstractThe gross and microscopic anatomy of the venom producing parotoid glands of Bufo alvarius has been studied by light and electron microscopy. Histochemical reactions for the presence of venom constituents and of components in biochemical pathways in the synthesis and release of venom were performed. The gland is composed of numerous lobules. Each lobule is an individual unit with a lumen surrounded by a double cell layer. Microvilli of the outer layer interdigitate with microvilli of the inner layer. Cells of the outer layer resemble smooth muscle cells, are rich in adenosine triphosphatase and glucose6‐phosphatase, and contain numerous pinocytotic vesicles, glycogen granules and various organelles, These organelles include “crystalloids” of what seem to be highly organized agranular reticulum. These outer layer cells probably function in some aspects of venom synthesis, active cellular transport and contraction in the discharge of the secretory product. The inner cell layer demonstrates a positive chromaffin reaction, contains steroid material, various organelles, some pinocytotic vesicles and glycogen granules, and appears devoid of a plasmalemma on its inner surface. This layer is probably involved in venom formation and release via an apocrine type of secretion.Bufo alvarius parotoid gland shows significant morphological and histochemical differences from that of B. marinus and more nearly resembles a typical steroid producing organ.
Burrowing in frogs
Authors: Emerson Sharon B. 
Published: February 2005

AbstractMore than 95% of burrowing Anura dig hindfeet first into the soil, a pattern unique to frogs among terrestrial vertebrates. The postero‐laterally placed hindlimbs and associated musculature of frogs are preadaptations for hindfeet digging. One fossorial, backwards burrower, Glyphoglossus molossus (Microhylidae), has morphological modifications of the hindlimb for positioning the spade‐like metatarsal tubercle and for increasing the force of the lower leg during digging.In contrast, in the headfirst burrower Hemisus marmoratus (Ranidae) there is extensive reorganization of the pectoral‐cranial morphology compared to that: of a non‐burrowing confamilial species. A model links the shifts in the pectoral morphology in Hemisus marmoratus to specific action patterns of headfirst: burrowing.Finally, data on stomach contents, natural history and energy utilization of frog species are presented to demonstrate the interrelationships of distinct loco. motor patterns with specific feeding strategies.
Ultrastructure of the vasa deferentia of the mediterranean flour moth
Authors: Riemann John G. , Thorson Barbara J. 
Published: February 2005

AbstractEach vas deferens of the Mediterranean flour moth, Anagasta kuehniella (Zeller), consists of a short swollen portion immediately below the testis, another swollen portion that forms a seminal vesicle, and an elongate lower portion that empties into one arm of the ductus ejaculatoris duplex. Three types of epithelial cells occur sequentially. Phagocytic cells that engulf debris from the testis form the anterior two‐thirds of the first swollen portion. Tall secretory cells form the distal third of the first swollen region and extend to the seminal vesicles. The secretory cells surround a slit‐like lumen and appear to function as a valve between the two swollen regions. Many membrane‐enclosed secretory granules are stored at the apical ends of the cells and are released into the lumen together with small amounts of the surrounding cytoplasm. The granules remain intact while they are in the male tract. A second type of secretory cell forms the walls of the seminal vesicles and the lower vasa deferentia. These cells produce secretory granules whose contents become dispersed through the semen. PTA‐chromic acid staining indicates that the seminal plasma has a high glycoprotein content. A thin muscle layer is basal to the epithelial cells. Both apyrene and eupyrene sperm undergo some development in the vasa deferentia. The epithelial cells, muscle, and stored sperm all undergo extensive changes with age.
The neck region of the spermatozoon of Discus rotundatus (Müller) (Pulmonata, Stylommatophora)
Authors: Maxwell W. L. 
Published: February 2005

AbstractThe neck region of the mature spermatozoon of Discus rotundatus is described. No evidence for a centriole or centriolar derivative is obtained. Nine striated coarse fibres and the two central fibres of the axoneme extend into the base of the implantation fossa. The axonemal doublet system is disrupted in the neck region. There are two fibrous accessory structures located between the central doublet and the striated coarse fibres.
Labellar taste organs of Drosophila melanogaster
Authors: Falk Raphael , Bleiser‐Avivi Naomi , Atidia Judith 
Published: February 2005

AbstractThere are 36 to 42 taste bristles on each half of the labellum of Drosophila melanogaster; most of them are two‐pronged with a pouch between them. Some end bluntly with a pore at the tip.Each taste‐bristle has two lumina: one is circular, the other crescent‐like in cross section. In most bristles four dendrites of chemoreceptor neurons run along the circular lumen. In five to seven taste‐bristles only two chemoreceptor neurons are found. A mechanoreceptor neuron sends a dendrite to the base of each taste‐bristle.The dendrites are surrounded by four concentrically‐arranged sheath cells. The inner cell secretes the cuticular sheath; cells II and III are presumably two trichogens, one secreting the bristle material around the circular lumen, the other around the crescent‐like lumen. Cell IV, especially rich in bundles of microtubules, secretes the cuticle of the socket, and corresponds to the tormogen. The neurons have the typical structure found in insect sensilla. In many sensilla one neuron is less electron‐dense than the others and may be the water‐sensor.On the medial side of the labellum between the pseudotracheae are rows of taste pegs covered by folds. In each peg one chemoreceptor and one mechanoreceptor are found.The number of axons in each labial nerve agrees with the total number of dendrites in all taste organs of each lobe.
Observations on the ultrastructure of developing myocardium of rat embryos
Authors: Chacko K. John 
Published: February 2005

AbstractTimed pregnancies were obtained in Sprague‐Dawley rats and early ultrastructural differentiation of myocardium of embryos of 10, 11, 12, 13, and 14 days was investigated and compared with that of newborn. Ten‐day myocardium is characterized by loosely packed cells; the cytoplasm is typified by a dearth of organelles. Both thick (myosin) and thin (actin) filaments become identifiable for the first time in the 10‐day myocardium where the heart is pulsating but circulation is not established. These filaments are not visible in the embryos of 9‐day‐old myocardium. The formation of these filaments is observed to continue throughout the period covered in this investigation. Concomitant with the appearance of the myofilaments is the synthesis of Z band material. By the eleventh day of gestation and during the subsequent days there is a rapid proliferation and differentiation of most of the organelles. The myofilaments become organized into fully formed striated fibrils. Intercalated discs appear as. small wavy lines on the eleventh day and become plicated in later stages and serve as cell boundaries and points of attachment for myofilaments and fibrils. There is a perceptible change in the number and morphology of mitochondria from the tenth to eleventh day and later stages of development when the heart becomes functional. Similarly, there is a rapid proliferation and differentiation of granular endoplasmic reticulum and Golgi bodies. Large quantities of free ribosomes are dispersed in the cytoplasm of 10‐day myocardium; however, in later stages there is a progressive reduction in the distribution of these particles. An intimate association of ribosomes and polysomes with the developing myofibrils is discernible. The T ‐system and sarcoplasmic reticulum begin to appear in II‐day myocardium. The embryonic myocardium displays intense mitotic activity throughout its development and a unique feature of embryonic myocardial cells is the simultaneous occurrence of myofilament synthesis and mitotic activity within the same cells.
Integumental organs of unknown function on chelipeds of deep‐sea crabs, genus Hypsophrys
Authors: Williams Austin B. 
Published: February 2005

AbstractHomolid crabs (Hypsophrys) from water deeper than 700 m in the Straits of Florida and Arabian Sea have smooth darkened oval spots contrasting with the surrounding roughened integument on inner and outer surfaces of each pincer at the base of the fixed finger. Cuticle is thinner over these spots than over surrounaing tissues. Beneath each spot is an organ composed of two markedly contrasting layers of tissue: (1) an outer, densely staining layer of tightly packed tubules, relatively straight and perpendicular to the overlying surface proximally but progressively convoluted and narrowed distally, finally ending blindly in association with the overlying thinned cuticle; (2) an inner layer of relatively large, eosinophilic, irregular cells with dark nuclei also trending at a right angle to the integument and bulging into the hemal sinus of the hand but separated from it by an epidermal lining. Droplets secreted from the inner layer apparently move into and along the tubules. Similar organs are known in no other crabs. The function is unknown but the structure suggests that they may be photophores.
Postembryonic ontogeny and functional anatomy of the ligamentum mandibulo‐hyoideum and the ligamentum interoperculo‐mandibulare, with notes on the opercular bones and some other cranial elements in Salmo gairdneri Richardson, 1836 (Teleostei: Salmonidae)
Authors: Verraes Walter 
Published: February 2005

AbstractThis study deals with the development of the opercular bones the ligamentum mandibulo‐hyoideum, the ligamentum interoperculo‐mandibulare and with some aspects of the development of the ceratohyale and the cartilago meckeli during postembryonic ontogeny of Salmo gairdneri (rainbow trout). It is stated that the ligamentum mandibulo‐hyoideum is present from hatching onward, while the development of the ligamentum interoperculo‐mandibulare appears during the period of active feeding. Some functional reasons are proposed to explain these facts. It is further suggested that the opercular bones develop under influence of the opercular muscles.
Comparative fine structural studies of planulae and primary polyps of identical age of the sea pen, Ptilosarcus gurneyl
Authors: Chia Fu‐Shiang , Crawford Bruce 
Published: February 2005

AbstractElectron microscopic study of an 18‐day‐old planulae and primary polyps of the sea pen, Ptilosarcus gurneyi, reveals 14 cell types: sustentacular cell A, sustentacular cell B, nerve cell, sensory cell, cnidoblast, interstitial cell, five types of gland cell (A, B, C, D and E), amoebocyte, style cell and endodermal cell. Of these, 9 are found in the planula, 12 in polyps and 7 are common to both stages. The fine structure of all cell types is described.Since the planulae and polyps in this study were identical in age of development, the gaining and losing of certain types of cells in the polyp are attributed to changes associated with settlement and metamorphosis. Modifications of the seven common cell types during metamorphosis can also be attributed to the change of life style from pelagic to benthic.
Initiation of the actinotrichial development in the early fin bud of the fish, Salmo
Authors: Géraudie Jacqueline 
Published: February 2005

AbstractUltrastructural analysis of initial development of actinotrichia, the skeleton anlage of the pelvic fin buds, was performed on the rainbow trout, Salmo gairdneri. It shows that the first actinotrichial rudiments appear in the subepidermal space of the pseudoapical cap. No mesenchymal cell bodies or their filopods are present. Hyaloplasmic protrusions of the basal epidermal cells are seen in the subepidermal space, limited by a dermoepidermal boundary reduced to a discontinuous thin adepidermal lamina without a collagenous layer. These morphological data suggest that the epidermal pseudoapical cap probably initiates the development of actinotrichia. Later, mesenchymal cells invade the subepidermal space and are probably involved in the further growth of actinotrichia.
Histological and histochemical studies on the nervous influence on minced muscle regeneration of triceps surae of the rat,
Authors: Mong Franz S. F. 
Published: February 2005

AbstractThe degree of minced rat muscle regeneration in the absence of nerve fibers was compared with that of normal regenerates between one and 270 days postoperatively. Up to around 30 days, the number of muscle fibers and their morphology were comparable in both normal innervated and denervated regenerates; both showed clear cross striations and peripherally located nuclei. Histochemically, SDH and myofibrillar ATPase (pH = 9.4) reactions were positive, but there were no typical signs of fiber types in either case of regeneration. The only consistent difference in the early period was the smaller fiber cross sectional areas in denervated regenerates than in innervated ones. Starting about 40 days, the muscle fibers in innervated regenerates became differented into different fiber types (fast‐twitch‐oxidative‐glycolytic, FOG., fast‐twitch‐glycolytic, FG., slow‐twitch‐oxidative, SO.) but there were no such activities in denervated regenerates, although their SDH and myofibrillar ATPase reactions remained positive for a long time. Degenerating muscle fibers could no longer be identified in innervated regenerates. In the denervated regenerates, however, muscle fibers underwent atrophic or degenerative changes and were replaced by connective tissue. The complete disappearance of muscle fibers varied with individual regenerates. In some cases, it occurred about 90 days and in others, traces of muscle fibers could still be seen as late as 150 days postoperatively. Thus, nerves seem to be important primarily in the late phase of regeneration; namely, differentiation of fiber types and maintenance of the structural integrity of muscle fibers.
Comparative study of the stomatogastric system of several decapod crustacea. I. Skeleton
Authors: Meiss Dennis E. , Norman Richard S. 
Published: February 2005

AbstractThe skeletal structure of the stomachs of several decapod Crustacea is described in detail. The general organization of the ossicles is similar for all species and the homologies of the elements can be recognized despite large variations from group to group. The Reptantia are characterized by a complex ossicle organization while the Natantia, on the other hand, are characterized by a simple organization. The various types of ossicle organization found in the decapod stomach can be arranged in a series ranging from simple to complex. The Brachyura have the most complex ossicle system and the Penaeidea the most simplified. This graded series of complexity closely follows the evolution of the Decapoda.
Some correlates of cranial and cervical morphology with predatory modes in snakes
Authors: Ruben John A. 
Published: February 2005

AbstractDissection of the cervical and basicranial regions in three species of snakes indicates that compared to Crotalus viridis and Lichanura roseofusca, Masticophis flagellum possesses relatively high numbers of compound axial muscle insertions on the atlas‐axis and vertebrae numbers 3‐5. It is suggested that the condition in Masticophis facilitates its vertical‐neck‐horizontal‐head foraging posture and has allowed axial muscles inserting on the dorsocaudal braincase in this snake to generate vertical and lateral head movements more effectively.
Embryogenesis of Xyleborus ferrugineus (Fabr.) (Coleoptera, Scolytidae). I. External morphogenesis of male and female embryos
Authors: Beeman Sylvia L. , Norris Dale M. 
Published: February 2005

AbstractA description of the external morphogenesis of male and female embryos of X. ferrugineus, derived from in vivo observation, is presented here. The embryogenesis of this beetle is typical of the Coleoptera, and is also similar in most respects to the generalized insect plan. Observed unusual aspects of X ferrugineus embryogenesis include the precocious formation of primordial g/rm cells and their temporary exclusion from the somatic blastoderm, the precocious in situ delineation of gnathal metameres, the closing of the gastral groove beginning at both ends and proceeding toward its middle, the formation of several paired lateral amnio‐serosal folds, the formation of cellular processes between the amnion and serosa, and the absorption of the thoracic limbs to produce an apodous larva. The embryonic developmental picture provided here, and the previously established means of rearing X ferrugineus in controlled laboratory culture jointly provide a promising basis for the further use of this insect in developmental studies.
Comparative studies on the structure of reproductive organs of four botryllid ascidians
Authors: Mukai Hideo 
Published: February 2005

AbstractReproductive organs of four botryllid ascidians, Botryllus primigenus, Botryllus schlosseri, Botrylloides violaceus and Botrylloides leachi, were studied histologically. In every species, the egg follicle consisting of an egg and its inner and outer follicles, is attached to the follicle stalk, the vesicle being composed of a flat epithelium, which in its turn is connected to the atrial epithelium or to the brood pouch specialized from it. In B. schlosseri, the egg is ovulated into the atrial cavity and remains there held by the brood cup, of which the inner epithelium is derived from the follicle stalk and the outer one from the atrial epithelium. In B. primigenus, the brood pouch develops as a diverticulum of the atrial cavity, around the entrance of which a fold differentiates from the atrial epithelium and closes the pouch during embryogenesis. In both species of Botrylloides, the brood pouch is formed by the outgrowth of the thickened atrial epithelium into the blood space, the entrance of which is closed during embryogenesis. The discarded outer follicle completely disintegrates soon after ovulation in B. schlosseri, but part of it remains throughout embryogenesis in the blood space in B. primigenus or projecting into the interior of the brood pouch in Botrylloides. In B. primigenus, the testis, when it accompanies the egg follicle, is placed at the bottom of the brood pouch and the sperm is shed through the pouch prior to ovulation. In B. schlosseri and the Botrylloides species, the testis is located independently from the egg follicle and the sperm matures after ovulation.