bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure of the green lacewing tympanal organ (Chrysopa carnea, neuroptera)
Authors: Miller Lee A. 
Published: February 2005

AbstractSmall swellings near the base of the radial vein in each fore wing of the green lacewing, Chrysopa carnea, resemble typical insect tympanal organs, but some important differences are apparent. The swellings are bounded dorsally and laterally by thick cuticle and ventrally by thin, membranous cuticle. The ventral membrane is formed by a single, thin sheet of exocuticle with flattened hypodermis internally, but lacks the tracheal component that forms part of the tympanum in the typical insect tympanal organ. The portion of the membrane beneath each swelling is rippled while proximally it is smooth. In contrast to typical insect tympanal organs, the swellings in C. carnea are largely fluid‐filled since an unexpanded trachea runs through each organ. A distal and a proximal chordotonal organ composed of typical chordotonal sensory units are associated with each swelling. The distal organ contains from five to seven units while the proximal organ is composed of from 18 to 20 units. Each sensory unit is composed of three readily identifiable cells. Distally, an attachment cell unites with the membrane and is contiguous with the scolopale cell, which surrounds the dendrite of the bipolar neuron. On the basis of the morphological evidence, one would not expect these swellings to function as sound receptors. However, the results of physiological and behavioral experiments, presented elsewhere, show that these organs are receptors for ultrasound.
Cuticle formation in the embryo of Drosophila melanogaster
Authors: Hillman Ralph , Lesnik Lorraine Heller 
Published: February 2005

AbstractIn Drosophila melanogaster embryos cuticle formation occurs between 12 and 16 hours of development at 25°C. The formation of the cuticulin and the protein epicuticular layers is simultaneous in the hypoderm, the tracheoblasts, and the fore‐ and hindgut cells. The cuticulin forms as a dual lamina, aggregating from granules secreted by the hypodermal cells. This is followed by the formation of a granular protein epicuticle and finally by the secretion of a mixed fibrous and granular endocuticle.All secretory cells are relatively simple in their ultrastructure. The secretory process is a membrane phenomenon, occurring at the tips of hypodermal microvillae on cells at the surface of the embryo and on those hypodermal cells lining the lumen of the fore‐ and hindgut. It also occurs along the entire surface of the tracheoblast lumen as well as on the outer surface of those cells which form exoskeletal chitinous setae. The process involves a specialization of the plasma membrane with the formation of secretory granules intracellularly beneath the membrane and the extrusion of these granules through the membrane to the outside where final cuticle formation occurs.
A histochemical study of the circumtesticular leydig cells of a teiid lizard, Cnemidophorus tigris
Authors: Currie Clyde , Taylor Harry L. 
Published: February 2005

AbstractSeveral oxidative enzymes in the testis of the teiid lizard Cnemidophorus tigris were studied histochemically. The cells of the circumtesticular sheath (Leydig cell tunic) are functionally equivalent to Leydig cells of the interstitium on the basis of similar histochemical reactions for the five enzyme systems studied. Both groups of cells were positive for 3β‐hydroxysteroid dehydrogenase, 17β‐hydroxysteroid dehydrogenase, NADH diaphorase, NADPH diaphorase, and glucose‐6‐phosphate dehydrogenase. These results support the hypothesis that the circumtesticular sheath has endocrine function as indicated by its vascularity and its ability to catalyze histochemical reactions involving steroid biosynthesis.
An histochemical and ultrastructural analysis of the dermal chromatophores of the variant ranid blue frog
Authors: Berns Michael W. , Narayan K. Shankar 
Published: February 2005

AbstractIntegument from blue and green areas of the variant blue frog were analyzed biochemically for pteridines and carotenoids. Solvent extraction and absorption spectrophotometry indicated that β carotene was greatly reduced in the blue skin, and present in high quantities in the green skin of the blue frog. Thin layer and paper chromatography indicated that the pteridines were almost totally lacking in the blue skin, and present in normal quantities in the green skin of the blue frog.Light and electron microscopy indicated that the xanthophore pigment cells were either greatly altered or absent from the blue integument and present in the green integument. The fine structure of the xanthphores of the green integument contained the normal ultrastructural components of xanthopores found in regular green integument. The blue integument contained an abnormal cell type that occupied the position in the dermal chromatophore unit normally held by the xanthophores. The possibility of these cells being abnormal xanthophores or some other cell type is discussed.
Seasonal ovarian histology of the ovoviviparous iguanid lizard Sceloporus jarrovi cope
Authors: Goldberg Stephen R. 
Published: February 2005

AbstractHistological analyses of monthly collections of Sceloporus jarrovi ovaries are presented. The ovaries undergo a cycle in which yolk deposition occurs in September‐October and is followed by ovulation in late November. One corpus luteum forms from each ruptured follicle and undergoes progressive cytoplasmic depletion until mid‐June parturition, after which time rapid degeneration commences. Follicular atresia is common during the spring and absent during the summer and early fall. Granulosa cells play an active role in follicular atresia luteal cell formation, and may also be involved in yolk deposition.
Cohesive properties of mammalian epididymal spermatozoa
Authors: Martan Jan 
Published: February 2005

AbstractChanging spermatozoan associations were observed in the epididymides of several mammals. These associations ranged from closely interwoven cylindrical bodies, found in the proximal part of the epididymis, to disorganized masses of spermatozoa, found in the distal part of the duct. It is suggested that changes in the cohesive properties of epididymal spermatozoa resulted in the formation and fragmentation of cylindrical bodies. These bodies, differeing in pattern and complexity according to the species, were found in all investigated mammals, including man. Cohesiveness appeared first in the upper part of the epididymidis, where it was confined to the spermatozoan tails. In general, there was a diminution of cohesive forces as the spermatozoa passed down the epididymal duct; consequently, the cylindrical bodies turned into disorganized masses of spermatozoa. There are indications that changes in the cohesive properties of spermatozoa may represent one aspect of spermatozoan maturation.
Respiratory significance of the external morphology of adults and fifth instar nymphs of Notonecta undulata Say (Aquatic heteroptera; Notonectidae)
Authors: Parsons Margaret C. 
Published: February 2005

AbstractThe bodies of adult and fifth instar Notonecta possess external air stores which are periodically renewed at the surface of the water. Both nymphs and adults have large ventral air stores on the thorax and abdomen and obtain atmospheric air at the posterior end of the latter; the adult also has dorsal subalar and supra‐alar air stores on both these regions. Ten pairs of spiracles open onto the air stores. Although the seven small, ventrally placed abdominal spiracles are probably both exhalant and inhalant in nymphs and adults, the three large anterior spiracles (mesothoracic, metathoracic, and first abdominal), which play a more important respiratory role, appear to function differently in mature and immature Notonecta. In the nymph they are probably both inhalant and exhalant, and communicate broadly with each other and with the ventral air stores. In the adult, however, they open onto separate, air‐filled chambers, each of which communicates differently with various parts of the air stores. Although all three probably function in exhalation, only the first abdominal spiracle, whose spiracular chamber is widely continuous with the dorsal and ventral air stores, appears to be well suited for inhalation.Several morphological features, most notably the development of long prothoracic lobes, separate spiracular chambers, and long, movable forewings, allow the adult a greater variety of respiratory modes than are available to the nymph. Some of the respiratory advantages of the adult are: (1) a larger amount of stored air; (2) a longer subalar air store, which can serve as an alternate pathway between the air stores and the atmosphere; (3) a greater capacity to utilize dissolved as well as atmospheric oxygen; (4) greater separation and functional specialization of the three anterior spiracles, thus allowing more separation of exhaled air from oxygen‐rich air on the external surface of the thorax; (5) the probable ability to regulate the continuity between various parts of the air stores, thus utilizing alternate pathways of air circulation and/or changing the functions of the three anterior spiracles; and (6) better protection of the latter against the entry of water during prolonged submergence.
Fine structure of the chemoreceptor sensillum in Limulus
Authors: Hayes Wilbur F. 
Published: February 2005

AbstractEach chemoreceptor sensillum of Limulus polyphemus consists of 6–15 bipolar neurosensory cells with distal processes confined within a single cuticular tubule as they extend to the outside environment. The cuticular tubule, which is enveloped by the cuticulo‐tubal cell, opens proximally into a fluid‐filled extracellular space through which the dendrite passes before entering the cuticular tubule. Between the neurosensory cells are one to three microvillar cells also exposed to the extracellular space. This space is enclosed by a sheath cell extending proximally from the inner opening of the cuticular tubule and enveloping the proximal portions of the dendrites, the distal portions of the microvillar cells, as well as the distal portion of some neurosensory cell bodies. Most of the remaining portions of the neurosensory cells and microvillar cells are enveloped by neuroglia. Tight junctions occur between the distal portions of the dendrites in or near the cuticular tubule. Each dendrite has a cilium‐like segment located where it traverses the extracellular space with a 9 + 0 pattern of fibers. Septuplelayered junctions occur among the proximal portions of some dendrites and some neurosensory cell bodies of the same sensillum. The subjacent processes of the sensillum frequently course proximally as isolated axons before joining nerve bundles. In the chilarial and gnathobasal chemoreceptors these nerve bundles course proximally to neuropile clumps of a peripheral nerve plexus. The presence of numerous synaptic vesicles in the neuropiles suggests that chemical transmission may occur among “en passant” synapses formed by the axons. Proximally the neuropiles are joined to the central nervous system by relatively long nerves.
Quantitative histology of changes with age in rat bone cortex
Authors: Singh I. J. , Gunberg D. L. 
Published: February 2005

AbstractChanges with age in bone cortex of the rat were investigated by establishing histological parameters which could be quantitated to estimate age at death. Decalcified cross sections of mandible, femur and tibia were prepared from rats two to 120 days old, and measurements were made of: (1) number of osteons, (2) average number of lamellae per osteon, (3) average Haversian canal diameter, and (4) number of non‐Haversian (primary) canals. Multiple regression techniques were used to estimate age at death from several combinations of these variables.With age, the number of osteons per unit area of bone and the number of lamellae per osteon increased, but Haversian canal diameter and the number of primary canals decreased. Multiple regression analyses indicated that age at death could be estimated to ± 3 days of the true value in 95% of the cases. Nomographs based on histological measurements of each bone were prepared which can provide accurate estimates of age between two and 120 days in the Sprague‐Dawley female rat. It was concluded that microstructure of bone cortex can not only be quantitated to provide accurate estimates of age but it may also constitute a sensitive measure of the metabolic state of the organism. The techniques utilized should prove useful in anthropology as well in studies of bone aging.
A re‐examination of the cloacal sacs and gland of the blind snake, Leptotyphlops dulcis (Reptilia: Leptotyphlopidae)
Authors: Kroll James C. , Reno Harley W. 
Published: February 2005

AbstractThe cloacal sacs of Leptotyphlops dulcis are nonglandular, posterior evaginations of the cloaca. The median cloacal gland is tubuloalveolar. Similar unpaired cloacal glands as well as paired sacs are noted in certain colubrid snakes. Terminology applied to these cloacal derivatives is discussed, and a standardization of names is provided.
Organogenesis in normal and lobeless embryos of the marine prosobranch gastropod Ilyanassa obsoleta
Authors: Atkinson James W. 
Published: February 2005

AbstractThe histogenetic and organogenetic capabilities of normal and lobeless embryos of Ilyanassa obsoleta are analyzed. Larvae developed from eggs in which the polar lobe was removed at the trefoil stage of first cleavage were studied in wholemount and section. None showed any evidence of eyes, statocysts, operculum, external shell, heart, or intestine. Sixty per cent of the wholemount larvae observed under polarized light exhibited internal masses of birefringent material resembling shell material. Of eight‐ to nine‐day lobeless larvae studied as stained, sectioned material 100% possessed muscle tissue; 97.5% possessed velar tissue, digestive gland tissue, and style sac tissue; 52.5% possessed two or more style sac areas; 71% exhibited esophagus; 63% possessed stomach tissue; 37% exhibited stomodeal‐like invaginations of the ectoderm; 31% exhibited a lightly staining ciliated area at the tip of the prevelar ectoderm; and 21% possessed glandular ectoderm resembling pedal or mantle gland tissue.The evidence presented suggests that the material of the polar lobe has an important role not only in cellular differentiation but also in the organization of tissue types into organs or organ primordia.
A light and electron microscopic study of the heart of a crayfish, Procambarus clarkii (Giraud). II. Fine structure
Authors: Howse Harold D. , Ferrans Victor J. , Hibbs Richard G. 
Published: February 2005

AbstractThe adventitia of the crayfish heart is composed of cells that are separated from each other by an intercellular space about 280 Å wide. Desmosomes are present on apposing surfaces of adjacent cells. A basal lamina underlies the adventitia and consists of a dense, amorphous substance that contains numerous fine filaments.The myocardial cells are striated and an external lamina 0.1 μ thick is present on the surface of the plasma membrane. The nuclei and most of the cytoplasm, glycogen and mitochondria are located at the cell periphery. The myofibrils are composed of thick and thin filaments and confined to the core of the cell. A T system and a well‐developed SR are present. Elements of these organelles form dyads at levels that correspond to the H bands, and triads at levels that correspond to the Z bands of the peripheral myofibrils. The relationship of the T tubules to the myofibrils is discussed.Locus cells exhibit a unique pattern of intracellular myofibrillar branching. They branch from a region which has a structure similar to the Z band material. The myofibrils radiate outwardly in various directions and form numerous cellular branches which form intercalated discs with adjacent myocardial cells. These discs are more complex than those observed in poikilothermic vertebrates but are simpler than those in mammals.An endocardium is lacking in the crayfish heart but interstitial cells are present in close association with the myocardial cells and neural elements. Terminal nerve processes deeply embedded in the myocardial cells are described.
Histogenesis of the lymphomyeloid complex in the larval leopard frog, Rana pipiens
Authors: Horton John D. 
Published: February 2005

AbstractA histological study was undertaken of the differentiation of the lymphomyeloid complex of larvae of the common leopard frog, Rana pipiens, reared at 18–21 °C. Immature lymphocytes are first recognised in the thymus and pronephros at stage I of Taylor and Kollros ('46). By the end of stage II, small lymphocytes are regularly found among the predominant larger lymphoid cells in the thymus, in which corticomedullary differentiation has begun. At this time, a few small lymphocytes are also apparent in the ventral cavity bodies, lymph gland, pronephros, mesonephros and intestine, but rarely occur in the spleen. During stages III and IV extensive development of these components of the lymphomyeloid complex occurs. The organs now contain large numbers of mature lymphocytes and have attained states of differentiation that remain essentially similar in subsequent larval stages. By stage V, small epithelium‐associated lymphoid accumulations are abundant throughout the length of the gastrointestinal tract. The anlagen of the procoracoid body and bone marrow appear just prior to metamorphosis.The kidneys are the main sites of blood formation in the larva. Masses of granulocytes are also usually found in the abundant ventral cavity bodies. A consideration of the roles of each of the organs provides insight into the ontogeny of the immune system of the Anura in general.
Antennal sense organs of the cockroach, Leucophaea maderae
Authors: Schafer Rollie 
Published: February 2005

AbstractAdult and nymphal antennae of the cockroach, Leucophaea maderae, contain nine or more different morphological types of sense organs. There is no outwardly apparent sexual dimorphism in adult antennae. Nymphs are dificient in gross numbers of sensilla. Sense organs are classified morphologically by their similarity to known types of sensila and are assigned functions on this basis and preliminary electrophysiological data: Sensilla chaetica (A), thick‐walled mechanoreceptive hairs in groups on the antennal base; S. chaetica (B), thick‐walled setae which are tactile and probably chemoreceptive, occurring in the antennal base and flagellum; S. trichodea (A), thin‐walled chemoreceptive hairs of the flagellum; S. trichodea (B), minute hairs on the scape and pedicel; S. basiconica, thin‐walled chemoreceptive pegs, and S. coeloconica („pit‐pegs”︁) of the flagellum; S. campaniformia and scolopidia, mechanoreceptors in the base and flagellum; plus Johnston's organ and/or connective chrodotonal organs in the pedicel. Calculations based on absolute counts of sensilla and their known innervation yield an estimate of about 3.3 × 104 sensilla and 105 cells per antenna.
The histology of the first batch of eggs and their associated tissues in the ovariole of Dysdercus fasciatus signoret (heteroptera: Pyrrhocoridae) as seen with the light microscope
Authors: Brunt Angela M. 
Published: February 2005

AbstractIn the telotrophic ovarioles of Dysdercus fasciatus, mononucleate, binucleate and multinucleate trophocytes are seen in the germarium. Cellular breakdown of the multinucleate cells is seen in the posterior part of this tissue. The nutritive cords, which are continuous with the trophic core at the one end and the oocytes of the vitellarium at the other, contain material of fibrous appearance which continues into the trophic core. The ovariole is enclosed in two sheaths throughout its length. Prefollicular tissue in the germarium appears to give rise to the follicle cells. Mitosis is common in this zone. Oocytes are at first surrounded by a multilayered epithelium. This is later reduced progressively to one layer. This one layered follicular epithelium is at first columnar but then changes to cuboidal mononucleate, cuboidal binucleate and finally to a squamous binucleate condition This epithelium thus seems to accommodate the increased volume of the oocyte by growth and a change of shape. The oocyte grows fastest at those times when it is surrounded by cuboidal and squamous epithelial cells.
Attachment and metamorphosis of the cheilo‐ctenostome bryozoan bugula neritina (linné)
Authors: Woollacott Robert M. , Zimmer Russel L. 
Published: February 2005

AbstractThe structure, attachment and subsequent metamorphosis of larvae of the marine bryozoan Bugula neritina were studied by light and electron microscopy.Two points of larval anatomy are of special significance to proper interpretation of the metamorphosis:

Two cytologically similar blastemal tissues, each laden with free ribosomes, occur as parts of the apical organ complex. The upper blastema directly contacts the larval surface, forming the non‐ciliated rows of the apical organ. The lower blastema is internal and is oral to and contiguous with the upper blastema.
The epidermal tissues of the larva are joined in the following sequence, beginning at the aboral pole: a. apical organ complex; b. apical‐connecting cell; c. infolded pallial sinus epithelium; d. vesicular‐connecting cell; e. aboral vesicular epithelium; f. corona; g. oral vesicular epithelium; and i., j., and k. internal sac neck, wall and roof regions.
The initial stages of metamorphosis involve a complex sequence of morphogenetic movements, including:

eversion of the internal sac, permanently attaching the larva to the substrate;
inrolling of the aboral vesicular epithelium, corona, oral vesicular and ciliated epithelia, and neck region of the internal sac into the larval interior; concomitantly the pallial sinus epithelium evaginates;
loss of connection between the invaginated tissues and the surface;
fusion of the pallial sinus epithelium with the wall region of the internal sac, maintaining the integrity of the body surface;
retraction of the apical organ complex and invagination of the pallial sinus epithelium with the simultaneous elevation of the internal sac wall region to the aboral pole.
At the conclusion of these events the preancestrular surface is covered by the wall and roof regions of the internal sac. Cells of the wall region form the epidermis of the body wall except for the attachment disc and secrete a cuticular exoskeleton that is secondarily calcified; the attachment disc is formed by the roof region of the internal sac.Internally, the ectodermal upper blastema differentiates into the lophophore and digestive tract of the ancestrular polypide, while the lower blastema forms the lining of the lophophoral coelom and the splanchnic (but not the somatic) lining of the visceral coelom. The visceral somatic peritoneum is formed from cells that may originate from the mesodermally derived pigmented cells of the larva to which they are similar in pigmentation and cytology. Such a composite derivation of a coelomic lining has not been described previously.