bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemoreceptor sensillum structure in Limulus
Authors: Hayes Wilbur F.
Published: February 2005

The chemoreceptors of Limulus polyphemus (L.) are polyneuronal sensilla found in the spines of the coxal gnathobases of each walking leg, the spines of the chilarial appendages, and the chelae of all the limbs. Each sensillum contains 6–15 bipolar sensory cells that share a single pore in the cuticle. The dendrites of the sensory cells of each sensillum course to the cuticle together. These attenuate sharply and enter a canal in the cuticle as a very narrow terminal thread. The dendrites retain their identity in the thread, but with the light microscope, they are usually not visible individually. Each thread, consisting of 6–15 dendrites, is accompanied to the cuticular surface by a cuticular tubule found within the canal. The chemoreceptor sensilla of the gnathobase, chilarium, and chela, the temperature organs of Patten, and the flabellar receptor organs all have the same basic organization. In general this is the same structural plan shown by chemoreceptors of other arthropods. Several different mechanisms of peripheral physiological interaction among receptor cells are possible with a sensillum organization like that described here for Limulus.
The development of the osteocranium of Pleurodeles waltlii Michahelles
Authors: Corsin J.
Published: February 2005

Under optimal conditions the development of the osteocranium covers the major part of the larval period and lasts about three and a half months. The earliest ossifications are of dermal origin and concern the tooth‐bearing bones. The poorly developed enchondral ossifications found in Urodela, appear at a much later stage, just before metamorphosis.
Segmental musculature and locomotion in Hermodice carunculata (polychaeta: Amphinomidae)
Authors: Marsden Joan Rattenbury
Published: February 2005

The segmental muscles in the intestinal region of the body of Hermodice carunculata are described as well as the gross anatomy of the associated nervous system.

The form of normal locomotion and the characteristic alarm reaction are described and interpreted in terms of fluid pressure within the body cavity and the action of appropriate groups of segmental muscles.

Brief remarks on the habits of H. carunculata conclude the paper.
Variation in the circumtesticular leydig cell tunic of teiid lizards (Cnemidophorus and Ameiva)
Authors: Lowe Charles H. , Goldberg Stephen R.
Published: February 2005

Testicular structure in bisexual teiid lizards (Cnemidophorus and Ameiva) is apparently unique among vertebrates in having a circumtesticular subtunic band of Leydig (interstitial) cells, that varies in species of Cnemidophorus from 1.2 to 42.1 cells in thickness (transverse cross‐section), between the outer tunic (tunica albuginea) and the seminiferous tubules. The regression on body size, ontogenetic change, seasonal periodicity, and other aspects of structure and function of this subtunic Leydig cell structure are discussed.
Histochemistry of the chick esophagus and trachea II. Enzymes, nucleic acids, proteins, carbohydrates, and fats
Authors: Hinsch Gertrude W.
Published: February 2005

Tissues of White Leghorn embryos of stages 17–45 and chicks of one day, two days, and three weeks of age were frozen, sectioned in a cryostat and, where appropriate, were fixed in cold calcium formol. Acid phosphatase, non‐specific esterase, adenosine triphosphatase, 5‐nucleotidase, non‐specific glycerophosphatase, nucleotidediphosphatase, and glucose‐6‐phosphatase were localized in these tissues. Ribonucleic acid, acid mucopolysaccharides, triglycerides, and neutral fats were localized in tissues fixed with FAA and embedded in paraffin.

Positive acid phosphatase reactions were obtained in the epithelium of the trachea and esophagus at all stages of development. 5‐nucleotidase was found in the muscularis mucosae of the esophagus at all stages. Non‐specific esterase appeared with histodifferentiation of the esophageal epithelium. Ribonucleic acid was localized in the basal regions of the epithelium.

Mucous glands of the esophagus are rich in ribonucleic acid and acid phosphatase at all stages of development. With histodifferentiation and the onset of secretion of sulfated acid mucopolysaccharides, the glands and their ducts become highly reactive for adenosine triphosphatase and nucleotide‐diphosphatase, indicating a role of these enzymes in secretion.
Structural changes in the murine yolk sac during gestation: Cytochemical and electron microscope observations
Authors: Calarco Patricia G. , Moyer Frank H.
Published: February 2005

Specimens of murine yolk sac prepared for light and electron microscopy at 8, 12, and 18 days of gestational age revealed a changing morphology of the endodermal cells in the visceral layer as gestation progressed. Basophilia increased between 8 and 12 days and decreased slightly between 12 and 18 days. These changes corresponded to the development of a highly organized rough‐surfaced endoplasmic reticulum by 12 days and its partial replacement by smooth‐surfaced elements by 18 days. Staining of frozen sections with tetrazolium dyes revealed a substrate dependent localization of the staining reaction within the cells and suggested an underlying compartmentalization of metabolic activities. Two types of apical granules were observed on the basis of both cytochemistry and electron microscopy. These granules were most numerous at 12 days of gestational age. The observations suggest that although synthesis and absorption doubtless occur simultaneously throughout gestation, the emphasis is on synthesis during the first half of the period and absorption during the second half. It is suggested that the change in fine structure may be due to the rupture of Reichert's membrane and the subsequent establishment of direct contact between the endodermal cells and the uterine wall.
Development of the gonads in Channa punctatus bloch (osteichthyes: Channidae)
Authors: Belsare D. K.
Published: February 2005

The history of the germ cells is traced from the time of hatching. The germ cells are larger in size and have faintly staining cytoplasm, clear cell outline and a distinct nucleus. They migrate by ameboid movement to reach the genital ridge and aggregate to lie against the gonadal epithelium prior to the formation of gonads. The germ cells are distributed along the gonad primordia.

The period of sex differentiation occurs between the 5.4 mm to 12 mm stage. The testis formation is recognized by the presence of germ cell nests and the sperm duct cord. The formation of the ovary is noted by the enlargement of the germ cells of uniform size and the development of the ovarian cavity.

The ovaries are described in four stages ranging from 21 mm to 135 mm fish. At 21 mm stage the ovarian cavity is continuous but is obliterated at 35 mm stage due to the projection of the ovigerous lamellae. The common opening for both the ovaries develops at 35 mm stage. The testes are described in four stages ranging from 23 mm to 135 mm fish. They differentiate more slowly and the first maturation division is seen at 90 mm stage.
Studies on the embryogenesis of Aulocara elliotti (Thomas) (Orthoptera, Acrididae). II. Developmental variability and the effects of maternal age and environment
Authors: van Horn Saralee Neumann
Published: February 2005

The stages of diapause embryos of A. elliotti reared in the laboratory were described, and the lengths of embryos of stage 19 were compared with a second group of diapause embryos of advanced ages. Collections of diapause embryos of the same species were made from wild populations during the autumn and winter of two consecutive years. The stages of embryos present in these samples were found to vary widely. The mean lengths of embryos in stage 19 from different populations were compared and found to differ with statistical significance. The numbers of retarded embryos in different populations were found to vary significantly between populations of diapause embryos. In two populations, mean lengths of embryos of stage 19 were found to differ from one year to the next.

Post‐diapause embryos were collected from wild populations in the spring of two consecutive years and their stages described. No significant difference was found in the incidence of retardation in post‐diapause samples. Results of these studies and those of other authors indicate that there may be wide developmental variation between populations of acridid embryos as well as in one population in two different years.

Rearing adult A. elliotti in varying numbers under two different environmental conditions was found to produce significant effects upon the rate of development and variability of their embryonic progeny. Embryos laid by young females were found to be more variable, in general, and to develop more slowly than those laid by older females.
Depletions in the cervical and thoracolumbar sympathetic system following removal of neural crest from the embryo of Chelydra serpentina
Authors: Yntema C. L.
Published: February 2005

Neural crest and dorsal neural tube of cervical and thoracolumbar levels were removed from embryos of Chelydra serpentina at stages ranging from 8 to 18 somites. Extirpation extended from the levels of the last four somites posteriorly around the neurenteric canal. Deficiencies in sensory and sympathetic ganglia occurred. Motor roots of the associated spinal nerves differentiated. In the absence of postganglionic neurons, the preganglionic fibers form a neuron‐free plexus in the thoracolumbar region. Some observations in the cervical region indicate that the postganglionic neurons depend on preganglionic fibers for their differentiation. The cortex of the adrenal gland formed without related medulla in appropriate experiments.

The normal morphology of the sympathetic trunks is illustrated. Superficial and deep cervical sympathetic trunks are described. The latter ascends the neck in a paravertebral position. Along its course are segmental ganglia and rami communicantes; it terminates by joining the medial branch of the superficial sympathetic trunk rostral to the ninth cranial nerve.
Placentation and associated aspects of gestation in the bonnethead shark, Sphyrna tiburo
Authors: Schlernitzauer Donald A. , Gilbert Perry W.
Published: February 2005

The left ovary of the bonnethead shark, Sphyrna tiburo, is rudimentary, and the right ovary supplies both oviducts which share a common ostium situated in the falciform ligament. Preceding ovulation the nidamental gland of each oviduct hypertrophies and the caudal two‐thirds of each oviduct is modified to form a uterus. In the Florida‐Caribbean area Sphyrna tiburo probably mates in March and 3–7 eggs are fertilized in the vicinity of the nidamental gland of each oviduct.

The developing embryo is nourished during the first 3–4 months of gestation by yolk stored in its extensive yolk sac. Approximately three and one‐half months after fertilization, the distal portion of the yolk sac becomes convoluted and interdigitates with deep folds in the uterine wall to form a yolk‐sac placenta. As the placenta develops, the maternal uterine epithelium is reduced from columnar cells to squamous cells, and the foetal yolk‐sac epithelium is reduced from columnar and cuboidal cells to squamous cells. Exchange between the maternal and foetal blood systems takes place through maternal endothelium, reduced maternal epithelium, egg‐case membrane, reduced foetal epithelium, and foetal endothelium.
Cardiac glycogen depletion in Amphiuma means during induced anoxia
Authors: Rose Francis L. , Zambernard Joseph
Published: February 2005

Giant salamanders, Amphiuma means, measuring 240 to 280 mm from snout to vent, tolerate induced anoxia for six hours. Most of the cardiac glycogen (beta units) is depleted within the first hour of anoxia but a few scattered units remain after six hours. The suggestion that cardiac glycogen is a stand‐by energy source which enhances the energy available to the heart during anoxic strain is reasonable. Beta units are stored in the heart as opposed to the larger alpha units in the liver. The smaller beta units are probably more easily metabolized than the larger alpha units due to their greater surface area per volume ratio and dispersal around the numerous cardiac mitochondria.
Observations on the ultimobranchial gland in small wild and laboratory mammals, with special reference to the histochemical localization of polysaccharides
Authors: Séhe Charles T.
Published: February 2005

This is the last of a series of observations involved in a comparative histological study of the ultimobranchial body in vertebrates. Complete serial longitudinal or transverse paraffin sections were made of formol alcohol, Bouin's, and formalin‐fixed ultimobranchial and thyroid tissues that had been removed from adult specimens of the cat, cotton rat, ground squirrel, Guinea pig, kangaroo rat, bushytailed wood rat, rabbit, and raccoon. The alcian blue‐PAS, aldehyde fuchsin‐alcian blue, mucicarmine, alcian blue‐safranin, Best's carmine, and toluidine blue staining procedures show that the glandular mammalian ultimobranchial tissue is capable of producing considerable amounts of various mucosubstances, particularly the acid mucopolysaccharides, and other carbohydrate‐containing materials. The carbohydrate moiety has been histochemically identified as mucopolysaccharides possessing acidic groups, those having both carboxyl and ester sulfate groups; and as glycogen, muco‐and glycoproteins and other carbohydrate‐protein complexes. The differences in the intensity and localization of a given staining reaction reflect not only individual and species variations but also significant differences in the position of the ultimobranchial tissue in relation to the thyroid gland. An accessory thyroid lobule found near parathyroid IV and thymus IV in a bushy‐tailed wood rat may represent a cystic manifestation of the ultimobranchial body because its follicles varied greatly in size and were lined by a thick stratified squamous epithelium. The possible hormonal mechanisms (TSH, thyroxine) involved in the regulation of ultimobranchial activity are discussed in relation to the gland's production, storage, and release of mucopolysaccharides and other secretory substances.
Tissue dynamics of steady state growth in Hydra littoralis. II. Patterns of tissue movement
Authors: Campbell Richard D.
Published: February 2005

In the column of hydra, tissues continually move away from a region located just underthe whorl of tentacles. Above this subtentacular region, tissues proceed into the hypostome and tentacles; below it tissues pass into the buds or continue down the stalk. These movements represent a steady state pattern of tissue renewal in which column growth is balanced by tissue loss at the body extremities. But the existence of a subtentacular zone in which tissue appears stationary does not necessarily indicate that growth is restrictedto this region, as is commonly stated.

The body column of hydra can be viewed as an expanding cylinder whose elongation is balanced by tissue loss at the two ends. In such a body there must be one region from whichtissue appears to emanate, regardless of how growth is distributed along the cylinder. Only the rates at which tissues move will be characteristic of the underlying growthpattern. In Hydra littoralis, the measured rates of tissue movement down the gastric column are consistent with the distributions of mitotic figures, which indicate that growth is spread out along the column.
The microscopic structure of the adult raccoon (Procyon lotor) and woodchuck (Marmota monax) spleens
Authors: Hayes Thomas G. , Eglitis John A.
Published: February 2005

Histological serial sections of spleens from the adult raccoon (Procyon lotor) and woodchuck (Marmota monax) were processed for microscopic examination. Observations related to various aspects of the internal vascular pattern in the spleen of the raccoon and woodchuck demonstrated features that were characteristic of the respective animal. The spleen of the raccoon possess well‐developed ellipsoid sheaths, whereas these same structures were not as prominent in the spleen of the woodchuck. The spleen of both mammals examined demonstrated the presence of an anastomosing series of venous sinuses within the red pulp tissue and may be classified as sinusal in nature.
The division and differentiation of Drosophila cystocytes
Authors: Koch Elizabeth A. , Smith Patricia A. , King Robert C.
Published: February 2005

Light and electron microscopical studies allow a descriptive account to be given of he morphogenesis of the egg chamber of Drosophila melanogaster. The study demonstrates that the mitotic products of a single cystoblast generate a branching chain of 16 inter‐connected cystocytes. Two specific cystocytes enter meiotic prophase, while the rest become nurse cells. The two pro‐oocytes form synaptinemal complexes in their nuclei. However, one of the two cells later switches back into the nurse cell developmental pathway. The elongation of the synaptinemal complexes is described, and estimates are made of the time involved in their formation. These complexes continue to be synthesized long after the DNA replication which gives the oocyte its 4C DNA content. This finding implies that at least some genetic crossing over follows DNA replication. Evidence is presented that cells undergoing crossing over are most efficient in repairing radiation‐induced chromosomal breaks. Suggestions are given as to the mechanisms by which (1) cell division is inhibited once 16 cystocytes are formed, (2) the future cleavage planes of cystocytes are programmed, (3) the pro‐oocytes are differentiated from nurse cells, and (4) the oocyte is chosen from the twin pro‐oocytes. The contrasting behaviors of the oocyte and nurse cell nucleoli are described. During oogenesis nucleolar synthesis of ribosomal RNAs is suppressed in the oocyte and concurrently stimulated in the nurse cells. It follows that the nurse nuclei are the major sources of the prodigious quantities of ribosomes found in the ooplasm of the mature oocyte.
Mathematical approach to measurements on embryonic chick lens
Authors: Wolpow Edward R. , Marimont Rosalind B.
Published: February 2005

Profiles of fresh chick lenses of 5, 8, 11, 14, 17 and 20 days embryological age were photographed and from tracings of these profiles, volumes were calculated using a formula for volume of a solid of revolution. Accurate volumes were also obtained by assuming the lens to be two half oblate spheroids of different minor axis, or, better, two half‐solids of profile (x/a)k + (y/b)k = 1. In addition, the k in this equation described well the curvature of the lens profiles and thus provided a quantitative measure of developing lens shape. Lens diameter, depth and shift of equatorial diameter upon lens axis as a function of age were also studied.
Cytological studies of the ductuli efferentes of the opossum
Authors: Martan J. , Hruban Z. , Slesers A.
Published: February 2005

Ductuli efferentes in four examined genera of family Didelphidae are organized into highly convoluted tubules, located within a conical body adjacent to the vascular plexus supplying the testis. They have yellowish‐green color in the adult Didelphis virginiana and grey pink color in other genera. The ductuli efferentes in all examined animals are lined by very low columnar cells, covered by microvilli or booth cilia and microvilli.

Histochemical analysis reveals several types of cytoplasmic granules in the genera examined. A single sperical body about 1.5 μ in diameter is found in epithelial cells of the four eyed opossum (genus Philander); this body stains positively for RNA and non‐histone protein, and appears granular under the electron microscope, without a limiting membrane. Abundant cytoplasmic bodies in the Virginia opossum show strong reactions for SH groups; these granules may be responsible for the green color of the ductuli in this species. Ultrastructural studies show that the morphology of membrane limited granules in the ductuli of the examined genera is characteristic for each genus. Abundant pinocytotic vacuoles in the apices of these cells and a strongly positive alkaline phosphatase reaction suggest a marked absorptive activity of epithelial cells.
Functional morphology of the head of the anabantoid teleost fish Helostoma temmincki
Authors: Liem Karel F.
Published: February 2005

Osteology, myology and motion analysis of the head of the anabantoid fish Helostoma temmincki, a specialized filter feeder, has revealed six functional units: neurocranium, suspensory apparatus, opercular apparatus, hyoid apparatus, branchial apparatus and pectoral girdle. Interactions between the functional units take place through four couplings involved in opening and protruding the jaws. The first coupling is activated in the beginning of the opening cycle by the levator operculi muscle through the opercular apparatus, interoperculomandibular ligament and mandible. The second is activated during feeding by contraction of the sternohyoideus through the hyoid apparatus, interopercular, interoperculomandibular ligament and mandible. The third coupling is active during feeding and “kissing” by contraction of epaxial muscles through mediation of the neurocranium to the jaw apparatus. The fourth coupling is the only one active during air intake and involves contraction of the levator arcus palatini which abducts and rotates the suspensory apparatus forwards, causing the mandible to drop. The retention of isolated ancestral characters during mosaic evolution are explained in terms of the maintenance of couplings which represent functional associations of seemingly remote structures. When natural selection acts on one component of a functional unit or coupling, it essentially acts on all associated elements simultaneously causing character complexes to evolve in common evolutionary trends. It is feasible that functional analysis can separate primary from secondary evolutionary trends.
Correlation of the development of membranous and bony labyrinths, acoustic ganglia, nerves, and brain centers of the chick embryo
Authors: Knowlton Valerie Y.
Published: February 2005

Detailed descriptions are presented of morphogenetic and histogenetic events occurring in the membranous and bony labyrinths, sensory areas, acoustic ganglia, and acoustic centers of the hindbrain of the chick embryo, stages 11 to 45. Major morphogenetic changes occur between stage 11 and stage 30. During this period primordial ganglionic neuroblasts are segregated from the otic epithelium and differentiate into the bipolar neuroblasts of the vestibular and cochlear ganglia, neuroblasts of the alar plate in the acoustic region of the rhombencephalon differentiate, migrate, and are organized into acoustic nuclei, and the otic cup closes to form a vesicle which undergoes complicated structural changes to become a labyrinth. Morphological events in neural structures are closely followed by structural changes in the labyrinth. Minor morphological changes continue to occur through stage 44. The histogenetic period, stage 26 to 38, is the same for all parts of the acoustic apparatus. Minor histogenetic events occur up to hatching. In this period, differentiation of ganglionic and central neurones precedes differentiation of sensory cells.
Studies on the neurosecretory system of Ranatra elongata fabricius (Hemiptera: Nepidae) with reference to the distal fate of NCC I and II
Authors: Dogra G. S.
Published: February 2005

With the help of PF and PAVB bulk‐stained preparations and sections the neurosecretory system of Ranatra elongata has been described. Two medial, each of 9‐10 cells, and two lateral, each of 3‐4 cells, groups of neurosecretory cells have been observed in the protocerebrum. Only the A‐cells have been found to be positive to PAVB histo‐ and cyto‐chemical technique. Axons of the A‐cells after traversing the proto‐ and deuto‐cerebrum emerge from the tritocerebrum as the NCC I. The NCC I after bypassing the corpora cardiaca penetrate the aorta wall. There is no physical continuity between the corpora cardiaca and the NCC I and the two are separable. The NSM from the A‐cells, transported by their nerve fibers, has been observed in the aorta wall. On the basis of large accumulation on NSM in the aorta wall the latter has been considered as the storage‐and‐release organ for the A‐material. Corpora cardiaca are found to be devoid of A‐material. Axons from the B‐cells, after emergence from the tritocerebrum as the NCC II, have been observed to penetrate the corpora cardiaca. On the basis of ample amounts of B‐material the glands have been considered as the storage‐and‐release organ for the B‐material only.

Observations are compared with results on related species and it is concluded that two independent organ complexes constitute the neurosecretory systemt of R. elongata. The A‐cells, their pathways, the NCC I, and the aorta wall comprise the first; and the B‐cells, their pathways, the NCC II, and the corpora cardiaca the second. The former is concerned with the elaboration, transportion, storage‐and‐release of the A‐material and the latter with the B‐material. Finally arguments are presented to include the aorta wall in the neurosecretory system.
The structure of the cochlea in chiroptera. III. Microchiroptera: Phyllostomatoidea
Authors: Pye Ade
Published: February 2005

The middle ear and the cochlea have been described in 20 representatives from the superfamily Phyllostomatoidea of the suborder Microchiroptera. Various measurements have been made and the results compared by means of graphs. The ultrasonic pulses used by these bats for echolocation have been recorded and analysed. Generally, the structure of the cochlea does not show extreme modifications as found in some other superfamilies that have previously been discussed.
Electron microscopy of the thymus in two species of snakes, Crotalus atrox and Lampropeltis getulus
Authors: Bockman Dale E. , Winborn William B.
Published: February 2005

The lymphoid cell population of thymus in the rattlesnake and king snake is similar to that of mammals. Lymphocytes occupy the interstices of an epithelial cell framework. An abudance of tonofilaments and desmosomes occupy the cytoplasm of epithelial cells with light, homogeneous nuclei and prominent nucleoli. Other epithelial cells contain phagocytized material in a dense cytoplasm which surrounds an irregular nucleus with heavily clumped chromatin. Small, granular vesicles are found within some epithelial cells.

Myoid cells occur in the medullary area. In mature forms, myofibrils are arranged in a concentric fashion around the nucleus and occupy much of the cytoplasmic volume. The presence of developmental stages of these cells suggests their differentiation within the thymus of the adult animal.
Splenomegaly and hemolytic anemia induced in rats by methylcellulose — an electron microscopic study
Authors: Wennberg Emina , Weiss Leon
Published: February 2005

Parenteral administration of methylcellulose causes massive splenomegaly and hemolytic anemia in rats. The red pulp of the spleen is markedly cellular due mainly to: (1) large numbers of voluminous free macrophages containing methylcellulose‐induced vacuoles, (2) an increase in the number of plasma cells and (3) stasis of blood evidenced by a large number of erythrocytes and platelets in vessels, sinuses and cords. White pulp changes are usually less marked. Here the major change is the presence of macrophages containing methylcellulose‐induced inclusions. The slow circulatory time in the spleen and the increase in macrophages may cause the hemolytic anemia observed in these animals.
Testicular characteristics of goldfish Carassius auratus, in nature and under diet limitations
Authors: Clemens Howard P. , Reed Carl A.
Published: February 2005

Goldfish testes were nutritionally regressed in about 115 days regardless of season and without controlled light or temperature. A gonosomatic index (testes weight ″ 100/body weight) of the regressed fish was about one tenth that of spawning fish. The regressed testes were primarily composed of spermatogonia, spermatocytes, and connective tissue. Fish testes were maintained in a regressed state for over 200 days with no change in gonosomatic index. Fish with regressed testes appeared to be in a state of “pseudohypophysectomy” with respect to gonadotropin. Pituitary replacement and a diet of 5% of the body weight per day initiated spermatogenesis and brought the regressed testes to functional maturity in one month. The results suggest that spermatogonial proliferation and the maturation of sperm have different regulatory requirements.
Ingestion of particulate matter by the outer surface cells of the mollusc mantle
Authors: Nakahara Hiroshi , Bevelander Gerrit
Published: February 2005

A study of the ingestion of particulate matter from the pallial space located between the shell and the outer surface of the mantle of Isognomon alatus and Pinctada radiata was undertaken with the aid of the electron microscope. For this purpose colloidal thorium dioxide (thorotrast) was introduced into the pallial space for periods of 1–5 days after which time the mantle was excised and prepared for examination with the electron microscope. After 24 hours thorotrast micelles were observed in the pallial space, on the surface of the microvilli, in small pinocytotic vesicles between the bases of the microvilli, in vacuoles undergoing coalescence and finally in large dense bodies (lysosomes). Amoebocytes in the pallial space also participate in the removal of particulate matter in a manner similar to that described for the surface epithelium. During active ingestion the Golgi apparatus changes from a vesicular to a lamellar form. The method of ingestion observed in the surface epithelia and the amoebocytes is similar to the ingestion of protein and other particulate material reported for a variety of vertebrate tissues.
Functional morphology and evolution of tail autotomy in salamanders
Authors: Wake David B. , Dresner Ian G.
Published: February 2005

Basal tail constriction occurs in about two‐thirds of the species of plethodontid salamanders. The constriction, which marks the site of tail autotomy, is a result of a reduction in length and diameter of the first caudal segment. Gross and microscopic anatomical studies reveal that many structural specializations are associated with basal constriction, and these are considered in detail. Areas of weakness in the skin at the posterior end of the first caudal segment, at the attachment of the musculature to the intermyotomal septum at the anterior end of the same segment, and between the last caudosacral and first caudal vertebrae precisely define the route of tail breakage. During autotomy the entire tail is shed, and a cylinder of skin one segment long closes over the wound at the end of the body.

It is suggested that specializations described in this paper have evolved independently in three different groups of salamanders.

Experiments and field observations reveal that, contrary to expectations, frequency of tail breakage is less in species with apparent provisions for tail autotomy than in less specialized species. The tail is a very important, highly functional organ in salamanders and it is suggested that selection has been for behavioral and structural adaptations for control of tail loss, rather than for tail loss per se.
Innervation of the respiratory muscles of Gallus domesticus
Authors: Dewet P. D. , Fedde M. R. , Kitchell R. L.
Published: February 2005

A detailed gross anatomical study of the innervation of the respiratory muscles was made on twenty mature, male, Single Comb White Leghorn chickens. The aim was to demonstrate the general pattern and degree of terminal branching of the intercostal and lumbar nerves that innervate respiratory muscles.

The point of entry for all nerves was on the medial face of the proximal third of the belly of the muscles, except for the transversus abdominis and costopulmonary muscles. The nerves were not always accompanied by blood vessels at the point of entry but both were invariably related at their terminal branches within the muscle belly and the tendon or aponeurosis. Within the muscle, primary, secondary, tertiary, and quarternary subdivisions of nerves coursed parallel to the muscle fibers, but some were tortuous. Plexus formation and/or segmental nerve anastomosis was most evident in strongly active expiratory and inspiratory muscles, i.e., all abdominal muscles and the m. costisternalis pars major.

A craniocaudal gradient in the size and development of the contractile mass of the intercostal muscles was observed. The mm. intercostales interni increased in size in the caudal intercostal spaces, while the reverse was true for the mm. intercostales externi. Variable forms and sizes of lateroventral abdominal muscles were observed and the m. rectus abdominis was consistently present.

The mm. intercostales interni and externi received branches from both the nn. intercostales interni and externi.
Hypothalamic neurosecretion in relation to water deprivation in ploceids of arid and swampy zones
Authors: Kripalani Kamla , Ghosh Asok , Rahman Hamidur
Published: February 2005

The effects of 72 hours of dehydration on the hypothalamo‐neuro‐hypophyseal system have been compared in three avian species which originate from different climatic habitats but belong to the same genus, Lonchura. In L. malacca, which is an inhabitant of swampy, non‐arid regions, the neurosecretory nuclei are activated and there is a depletion of neurosecretory material from the nuclear regions and neurosecretory tract, as well as from the neurohypophysis. In L. punctulata, an inhabitant of woods and grasslands, the supraoptic cells show signs of activation. To some extent, a depletion of the neurosecretory material is observed from the neurohypophysis. In the fibrous layer the continuity of the neurosecretory material along the tract is not maintained to such an extent as in the control. In L. malabrica, which lives in semi‐arid regions, there is some activation of the supraoptic nuclei but there is little to no depletion of the aldehyde fuchsin‐positive material from the neurohypophysis and the tract leading to it. The results of this investigation are indicative of a correlation between the neurosecretory mechanism and ecologic adaptation.
Cytoplasmic filaments and associated lucké viruses in the frog renal adenocarcinoma
Authors: Lunger Philip D.
Published: February 2005

The morphology and possible functional significance of cytoplasmic filaments associated with herpes‐like viruses of the frog renal carcinoma is described. Filaments, invariability arranged in elongated bundles or sheaths, individually measure approximately 30 mμ in diameter, and are composed of finely granular, proteinaceous material. During the viral maturation sequence, this material is believed to be deposited on the surface of the capsid, thereby possibly providing the virus with a defensive coating prior to ergression from the cell.
The development of the insect nervous system. I. An analysis of postembryonic growth in the terminal ganglion of Acheta domesticus
Authors: Gymer Anne , Edwards John S.
Published: February 2005

This study describes the post‐embryonic growth of the terminal ganglion in Acheta domesticus in terms of volume and cell number. All measurements were made at the beginning of each instar from hatching until the final moult on animals reared under controlled conditions. The terminal ganglion increases about 40‐fold in volume from 2 × 106 μ3 in the first instar to 85 × 106 μ3 in the adult. A double logarithmic plot of ganglion volume against body weight shows that the ganglion volume is a function of body weight to the 0.56 power. Initially the neuropile grows at a greater rate than the cortex; in later stages they increase at the same rate.

Increase in cell number was determined from serial sections. The total number of cells, based on corrected nuclear counts, increases from 3,400 to 20,000. There is little or no increase in the number of neurons. There are approximately 2,000 association neurons and 100 motor neurons in all stages. The number of glial cells increase from 1,000 to 17,000. Their multiplication rate appears to be related to the increase in neuron volume.

Despite the increase in glial cell number, increase in cell volume is primarily responsible for the increase in total volume of the ganglion.
Functional anatomy of the heart of the fruit‐eating bat, Eidolon helvum, Kerr
Authors: Rowlatt Ursula
Published: February 2005

Seventy‐seven hearts from one species of bat, Eidolon helvum Kerr, have been examined as a preliminary step in correlating cardiac form the and function in relation to flight in mammals. The supposition is that the heart, like the upper limbs and pectoral girdle, will show deviations from the common mammalian plan because of the animal's unusual way of life.

The first thing that happens in flight, as in any form of exercise, is an immense increase in venous return to the heart. The architecture of the sinus venarum of the right atrium and of the right ventricle in the region of the atrioventricular valve, including the position of the papillary muscles, may be related to prevention of rapid overdistension of the right side of the heart. The walls of the inflow and outflow tracts of the right ventricle are exceptionally smooth, an anatomical feature that may have significance in that friction may be reduced. The left side of the heart resembles that of other mammals more closely.
The fine structure of tissues in the amputated‐regenerating limb of the adult newt, Diemictylus viridescens
Authors: Norman Wesley P. , Schmidt Anthony J.
Published: February 2005

We have examined the fine structure of injured, repairing and regenerating tissues of the amputated forelimbs of the adult newt: observations were made on wound epithelium, nerves, striated muscle, the regeneration blastema, connective tissues and cartilage.

The wound epithelium shows little modulation from the adjacent epidermis: a subjacent glycocalyx and hemidesmosomes are initially absent. Some cells reveal phagocytic activity. As regeneration progresses, a glycocalyx, hemidesmosomes, and an adepidermal reticulum of fibers develop.

Nerve fiber degeneration and regeneration lie side by side in the same nerve bundle. Myelin degeneration is evident within 24 hours; neural connective tissues loosen and fibers appear to spread apart.

Striated muscle fibers display a nonuniform response to trauma, due to unequal degree of injury inflicted by amputation. The moderately and greatly injured fibers lose their distal fibril organization. There is a numerical increase in mitochondria, and occasionally a pyknotic nucleus is present. The myofiber glycocalyx appears to resist destruction, even when cell degeneration is extensive. Satellite cells have been observed intimately in contact with injured myofibers. Myogenesis is accompanied by an increase in collagen fibrillogenesis associated with adjacent fibroblasts. Many of these latter cells appear to contain intracellular fibrils: the significance of these observations are discussed, and a basis for intracellular fibrillogenesis and tropocollagen accretion is proposed.

The fine structure of the regeneration blastema cell agrees with the description offered by others for the adult newt limb regeneration.

Early prochondral condensation of blastema cells is described briefly.
Experimentally induced variations in vitelline artery development and circulatory pattern in the early chick embryo
Authors: Levenson Gordon E. , Nelsen Olin E.
Published: February 2005

White Leghorn eggs were incubated to desired prevasular stages. Each embryo, upon its intact yolk and surrounded by albumen, was rolled from the shell into a sterile 50 ml beaker. In an uppermost position, the blastoderm was lightly stained with neutral red. Three types of localized cuts were made as indicated below, and the beaker‐embryo unit placed in a sterile humidified chamber for further incubation. Results: (1) Unilateral cuts adjacent to the body and parallel with its axis blocked or suppressed formation of the vitelline artery on the cut side, even though healing occurred; (2) A specific site was found in the area pellucida opposite the sinus rhomboidalis which, when lightly cut perpendicular to the body axis, resulted in blockage or shifting of the final junction between aorta and vitelline artery as far cephalad as the thirteenth somite level. Formation of a dual final junction with the aorta also occurred. (3)Transverse cuts through the body axis and into the area pellucida bilaterally, frequently resulted in bilateral blockage or bilateral shifting. In still other cases, growth of a functional loop around the cut to connect the aortae in anterior and posterior segments with the vitelline artery were observed. Other unique circulatory patterns are described.

Apparently, slight interference with the capillary plexus which precedes the vitelline artery causes anomalous development. Circulation is considered a major factor in arterial differentiation. Cutting probably alters the plexus and relation of its components to the onset of blood flow.
The post‐embryonic changes in Melipona quadrifasciata anthidioides lep. (hym. apoidea) II. Development of the salivary glands system
Authors: Cruz‐Landim Carminda Da , Mello Maria Luiza Silveira
Published: February 2005

The paper deals with the development of the salivary gland system in Melipona quadrifasciata anthidioides, which begins in the prepupal stage. The silk glands degenerate by autolysis at the end of the larval stage. Degeneration is characterized by cytoplasmic vacuolization and pycnosis of the nuclei of the secretory cells. The glandular secretory portion of degenerated silk glands separates from the excretory ducts. The salivary glands develop from the duct of the larval silk glands. The thoracic salivary glands develop from the ducts of the secretory tubules and the head salivary glands from the terminal excretory duct. The mandibular glands appear in the prepupa as invaginations of mandibular segments, and their differentiation to attain the adult configuration occurs during pupation. The hypopharyngeal glands have their origin from evaginations of the ventral anterior portion of the pharynx. A long tubule first appears with walls formed by more than one cellular layer. Then some cells separate from the lumen of the duct, staying attached to it by a cuticular channel in part intracellular. The initial duct constitutes the axial duct, in which the channel of the secretory cells opens. During the development of salivary and mandibular glands, they recapitulate primitive stages of the phylogeny of the bees. During the development of salivary glands system, mitosis accounts for only part of the growth. Most of the growth occurs by increase in size of cells rather than by cell division. In brown‐eyed and pigmented pupae six days before emergence, the salivary gland system is completely developed, although not yet functioning.
Aspects of the fine structure of the intrahepatic bile duct epithelium in normal and cholecystectomized mice
Authors: Yamada Kazuyori
Published: February 2005

The epithelium lining the intrahepatic bile ducts of normal adult mice consists of a single layer of cuboidal or low columnar cells and has ultrastructure comparable to that described previously (Rouiller and Jézéquel, '65). Some of the epithelial cells, however, exhibit such particular features as dilatation of granular endoplasmic reticulum cisternae, polysome formation of ribosomes and the presence of active forms of the Golgi apparatus, numerous lysosome‐like bodies and apical projections and blebs. Postnatal cholecystectomy does not induce any qualitative changes in the epithelial fine structure, but results in a significant increase in number of the particular structures mentioned. Therefore, the cholecystectomy is thought to stimulate the secretory activity of the epithelial cells, and such stimulation appears due to the absence of a possible activity of epithelial secretion in the gallbladder.
The pituitary in polypterines and its relationship to other fish pituitaries
Authors: Kerr T.
Published: February 2005

The structure and cell types of the closely similar glands of Calamoichthys and Polypterus are described and a general comparison made with the teleost pituitary. The Polypterine gland shows some unsual features in the anatomical disposition of its parts and in the arrangement of its neurosecetory and vascular supply and an explanation of these differences is suggested, based on relative growth changes in later development, in order to include these glands in the evolutionary pattern of the actinopterygian pituitary.
The fine structure of wound repair in an insect (Rhodnius prolixus)
Authors: Lai‐Fook Joan
Published: February 2005

The cells surrounding a wound in the integument of Rhodnius adults show an increase in RNA content, cytochrome oxidase and esterase activity. An excision in the integument is filled by blood which coagulates and is tanned into an insoluble membrane. The basement membrane of the adjoining epidermis acts as a self‐sealing membrane and contracts to cover the excision. The epidermis is attached to the cuticle by the subcuticular layer which it resorbs and by pore canal filaments which are left behind as it migrates. The epidermis migrates as a sheet in contact with the cuticle then with the coagulated blood and basement membrane which cover the excision. Blood cells migrate individually into an excision and do not adhere to a surface in the process. Microtubules cannot be identified with movement. Both epidermal and blood cells remove the cells killed by wounding as evidenced by the appearance of coated vesicles and phagocytic bodies in both cell types. The reconstituted integument consists of a surface membrane in which the layers of the epicuticle are not distinguishable, a nonlamellate cuticle secreted by an epidermis which also appears to secrete the new basement membrane.
Myocardial ultrastructure and electrocardiograms of the sloth (Bradypus tridactylus) under normal and experimental conditions
Authors: DiDio Liberato J. A.
Published: February 2005

Adult sloths (Bradypus tridactylus) were studied by electrocardiography and by light and electron microscopy under normal conditions and under experimental conditions as provided for by injection of 2,4‐dinitrophenol (DNP) and ether anesthesia. ECG's of the animals indicated heart rates of 45–71/min, which can be considered as the normal heart rate of the sloth under laboratory conditions. Under normal conditions, the contracted ventricular myocardium of the sloth exhibited (a) a wrinkled sarcolemma, (b) the usual pattern of myofibrils and of sarcoplasmic reticulum, (c) small mitochondria with spiked and branched, often anastomosed cristae, including a few small intramitochondrial dark bodies, (d) an amount of sacrcosomes smaller than the amount of myofibrils, (e) many glycogen granules, isolated, in the form of a chain, or as clusters, in subsarcolemmal, intermyofilamentous and perimitochondrial positions, (f) few multivesicular bodies and (g) large flat sections of the transverse tubular system.

Injection of DNP (1 mg/kg) caused tachycardia. With ether anesthesia, the ECG showed monophasic action potential of myocardial injury and prolongation of inter or intraventricular condition. Electrically, the sloth's heart responded to hypoxia as do other mammalian hearts.

The administration of DNP produced (a) derangement and reduction in number and length of the mitochondrial cristae, (b) disappearance of spikes, connections between the cristae and, consequently, the honeycombed arrangement, (c) increased matricial space in the center of mitochondria which was often filled with a grayish substance, (d) disappearance of small dark intramitochondrial granules, (e) depletion of glycogen particles and (f) few dilations in the sarcoplasmic reticulum.