bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allometry of the limb long bones of insectivores and rodents
Authors: Bou J. , Casinos A. , Ocaña J. 
Published: February 2005

AbstractIn an attempt to investigate the relationships between allometry and locomotory adaptations, we studied the long limb bones of 45 species of insectivores and rodents. Animals ranged from a few grams to about 50 kilograms. Diameter and length of the bones and body mass (when known) were recorded. Regressions of diameter to length, diameter to body mass, and length to body mass were calculated by the least‐squares and Model II, or major axis, methods.The results obtained do not agree with the predictions of either the theory of geometric similarity or the theory of elastic similarity. The discrepancies could be due to the fact that animals studied exhibit various modes of locomotion. Moreover, the allometric relationships of the different locomotor patterns are better reflected in insectivores and rodents than in other groups of mammals. The use of a single regression analysis seems to be inadequate when the sample includes a large range of body sizes.
Histochemistry of the lung of the Australian snake‐necked tortoise chelodina longicollis
Authors: Smith R. V. , Satchell D. G. 
Published: February 2005

AbstractThe innervation and structure of the lung of the Australian snake‐necked tortoise, Chelodina longicollis, was examined by using light microscopy including fluorescence histochemical techniques. The anterior lung was divided into a number of compartments with numerous alveolar spaces. The posterior lung was simpler and saclike in structure and alveolar spaces were absent. Smooth muscle fibers occurred in discrete muscle bands and in the walls of the septal bands. Ganglion cells occurred along nerve trunks throughout the lung but were more numerous in the posterior lung. Smooth muscle bands, the extrinsic pulmonary artery, and the arteries within the lung were sparsely innervated by adrenergic fibers. Substance P‐containing sensory fibers were not demonstrated. The innervation and structure of the lung are compared to published work on other reptiles.
Ultrastructural changes in the intestinal connective tissue of Xenopus laevis during metamorphosis
Authors: Ishizuya‐Oka Atsuko , Shimozawa Atsumi 
Published: February 2005

AbstractUltrastuctural changes in the intestinal connective tissue of Xenopus laevis during metamorphosis have been studied. Throughout the larval period to stage 60, the connective tissue consists of a few immature fibroblasts surrounded by a sparse extracellular matrix: few collagen fibrils are visible except close to the thin basal lamina. At the beginning of the transition from larval to adult epithelial form around stage 60, extensive changes are observed in connective tissue. The cells become more numerous and different types appear as the collagen fibrils increase in number and density. Through gaps in the thickened and extensively folded basal lamina, frequent contacts between epithelial and connective tissue cells are established. Thereafter, with the progression of fold formation, the connective tissue cells become oriented according to their position relative to the fold structure. The basal lamina beneath the adult epithelium becomes thin after stage 62, while that beneath the larval epithelium remains thick. Upon the completion of metamorphosis, the connective tissue consists mainly of typical fibroblasts with definite orientation and numerous collagen fibrils. These observations indicate that developmental changes in the connective tissue, especially in the region close to the epithelium, are closely related spatiotemporarily to the transition from the larval to the adult epithelial form. This suggests that tissue interactions between the connective tissue and the epithelium play important roles in controlling the epithelial degeneration, proliferation, and differentiation during metamorphic climax.
Morphology, sense organs, and regeneration of the forelegs (whips) of the whip spider Heterophrynus elaphus (Arachnida, Amblypygi)
Authors: Igelmund Peter 
Published: February 2005

AbstractIn the whip spider Heterophrynus elaphus the first pair of legs is specialized to serve sensory functions. The morphology of these “whips” and the sensory organs of their tarsi and tibiae are described using scanning and transmission electron microscopy. The tarsus is normally subdivided into 74 segments and bears 7 types of sensory hairs: bristles, club sensilla, two types of porous sensilla, two types of rod sensilla, and leaflike hairs. In addition there are modified claws, 3 kinds of slit sense organs, a “pit organ,” a “plate organ,” and probably a joint receptor. The tibia is usually subdivided into 33 segments. In addition to bristles the tibia bears 7 trichobothria at constant locations and a lyriform slit sense organ. The functional and systematic implications of these findings are discussed.
Cytological and cytochemical investigations of development from dormant gemmules of the marine sponge, Haliclona loosanoffi
Authors: Jetton Thomas L. , Fell Paul E. , Harrison Frederick W. 
Published: February 2005

AbstractVernalized gemmules of the marine sponge Haliclona loosanoffi were cultured at 20°C, fixed at 24‐hour intervals (0–11 days), and processed for light microscopy by using a variety of absorption and fluorescent staining methods. The cytochemistry and morphology of development were compared to the well‐studied developmental patterns of freshwater sponges and to the patterns described in the marine sponge Suberites domuncula. The precocious development of H. loosanoffi gemmules involves early morphogenesis occurring within the unhatched gemmule, as opposed to the patterns in freshwater sponges, where most development occurs after the gemmule hatches. Definitive sponge tissue surrounding a single osculum is present 9 days after release from dormancy.
Development of the head skeleton of the Japanese medaka, Oryzias latipes (Teleostei)
Authors: Langille Robert M. , Hall Brian K. 
Published: February 2005

AbstractThe identification, spatial relationships, and sequences of development of the cartilaginous and bony elements of the chondrocranium, osteocranium, and splanchnocranium in the medaka, Oryzias latipes, are described here for the first time. The development of the cartilaginous head skeleton commences at stage 29 and is essentially complete by stage 35 (hatching). The parasphenoid bone and two pairs of branchiostegals are present at this stage and several other replacement and dermal bones begin to appear shortly thereafter. Development of the osteocranium and ossification of the splanchnocranium continue throughout the larval and juvenile phases and are essentially complete at sexual maturity at approximately 3 months (at 25°C), at which time the fish range in length between 25 and 30 mm.The description of the adult head skeleton of O. latipes is compared to those of O. melastigma, O. luzonesis, and other Oryzias spp. previously described and a redesignation of the relationships between certain elements in the adult head skeleton is proposed, based on the developmental data presented. Furthermore, the value of the medaka as a model teleost to study the embryological origins of, and in particular, the neural crest contributions to, the cranial and visceral skeleton is outlined based on certain characteristics of the medaka's life history traits. These include the ease of obtaining embryos for which the exact time of fertilization is known (without sacrificing any brood stock) and the relatively rapid development of the chondrocranium, which is nearly complete at hatching, a process which can occur in as short a time as 6 days (at 34°C). The usefulness of the ontogenetic data obtainable from further studies into the embryonic origins of head and visceral skeletal elements revealed in the present study, is briefly discussed.
Regeneration of the eighth nerve fibers after transection in the red‐eared turtle, Chrysemys scripta elegans
Authors: Marbey Debra A. , Browner Robert H. 
Published: February 2005

AbstractThe present study examined the time sequence of degeneration and regeneration after transection of the eighth nerve in the red‐eared turtle as well as the chromatolytic reaction of the turtle auditory ganglion cells. Horseradish peroxidase (HRP) transport between auditory ganglion cells and the medulla identified eighth nerve connections. The course of eighth nerve degeneration was followed with Fink and Heimer degeneration stain and HRP reaction. Cresyl‐violet‐stained sections through auditory ganglion cells were observed for chromatolysis.Degeneration by‐product was intense in the eighth nerve and primary auditory nuclei in turtles surviving 25 and 32 days after eighth nerve transection. Turtles surviving 45 days or less after eighth nerve transection showed HRP reaction product in the eighth nerve to the point of its dorsolateral penetration into the medulla following cochlear duct injections. Acoustic tubercle injections in 50‐day survivors showed HRP filling in eighth nerve and auditory ganglion cells. Cochlear duct injections in 67‐day survivors demonstrated HRP filling in the eighth nerve and acoustic tubercle. Sections stained for degeneration in 67‐day survivors showed little or no degeneration by‐product and 80‐ and 90‐day survivors showed none.The proportion of chromatolytic auditory ganglion cells was greatest in the 50‐day postoperative turtles when compared to control turtles and other survival stages. Animals which survived longer than 50 days had reduced numbers of chromatolytic cells.Results suggest that the eighth nerve fibers are regenerated to primary brainstem auditory nuclei in experimental turtles surviving 50 days or more. Regeneration occurs between the 45th and 50th day following transection.
Fine structure of the foveae dorsales and foveal glands in the female tickAmblyomma americanum(acari: Ixodoidea: Ixodidae)
Authors: El Shoura Samir M. 
Published: February 2005

AbstractThe fine structure of the paired foveae dorsales and foveal glands in the unfed femaleAmblyomma americanumis described and compared with that in other tick species. Each fovea opens to the exterior via pores which lead internally into a single cuticular tube, the pore‐tube. This is surrounded by 2–3 epithelial cells. The pore‐tube enlarges basally forming a large cavity possessing a cup‐shaped cytoplasmic protrusion. The pore‐tube cuticular lining extends downward to form an electron‐dense, flaplike protrusion bracketing narrow cytoplasmic extensions filled with microtubules. These extensions form a previously undescribed valvelike structure that seems to control the flow of pheromone secretion from the foveal gland to the pore‐tube.The single foveal gland lying beneath each pore‐tube is composed of 2–3 inner, large, storage cells surrounded by outer, spindle‐shaped cells; both types of cells have a characteristic feature of epithelia involved in secretory activity and ion transport. The outer cells extend upward to join the base of the poretube cells by septate desmosomes. A nerve, the foveal nerve, containing axons with neurosecretory vesicles occurs in the vicinity of the foveal gland. The secretory activity of the pheromone glands seems to be partially, if not entirely, under a neural regulation.
Observations on the fine structure of the baroreceptors and adrenergic innervation of the guinea‐pig carotid sinus
Authors: Shin H. S. , Hulbert W. C. , Biggs D. F. 
Published: February 2005

AbstractWe examined the fine structure of the baroreceptors and the adrenergic innervation of the guinea‐pig carotid sinus. The tunica adventitia contained many nerve bundles whose perineuria enclosed unmyelinated nerve fibers, alone or together with myelinated nerve fibers. Baroreceptors, which lay close to elastic and collagen fibers in the adventitia and media, were surrounded by “terminal” cells with ultrastructural features characteristic of Schwann cells and contained inclusions of various types. Morphologic features of the baroreceptors included densely packed mitochondria, osmiophilic lamellated and homogeneous bodies, clear and granular vesicles, lamellar systems, glycogen granules, neurofilaments, neurotubuli, and vacuolated mitochondria. In animals that had been treated with 6‐hydroxydopamine, occasional electrondense endings (or fibers) were observed in the adventitial layer. The baroreceptors in the guinea‐pig carotid sinus appear to have most of the morphologic features reported for other species.
Functional characteristics of rat gastrocnemius and tibialis anterior muscles during growth
Authors: De Koning J. J. , Van Der Molen H. F. , Woittiez R. D. , Huijing P. A. 
Published: February 2005

AbstractSeveral morphological and functional characteristics of the rat gastrocnemius medialis and tibialis anterior muscle were studied in young, adult, and old rats to assess the influence of growth. Antagonist muscles were studied to determine how changes of muscle architecture and functional characteristics are influenced by the demands of increased body weight and by the specific roles of these muscles in locomotion.Both muscles change drastically, for instance, in muscle length, volume, physiological cross‐sectional area aponeurosis length, and their muscular geometry changes allometrically for both muscles. The relationships between muscle length, distance between origin and insertion, tendon length, and tibial length also change with growth. Both muscles are rather pennate, so that the increase of physiological cross‐sectional area is a major factor in the determination of muscle length.No significant difference could be shown for fundamental physiological characteristics (i.e., functional characteristics normalized for muscular dimensions such as maximal work per unit volume). The changes of morphological and functional variables of both muscles parallel each other as is apparent from the index of antagonist characteristics, which is constant for all variables studied with the exception of muscle volume and tendon length.Consequently, the considerable and similar changes of TA and GM morphology and functional characteristics that take place during growth from approximately four weeks postnatally is not caused by changes of muscular material but by changes of the amount and architectural arrangement of the material involved.
The growth of the skull and jaw muscles and its functional consequences in the New Zealand rabbit (Oryctolagus cuniculus)
Authors: Weijs W. A. , Brugman P. , Klok E. M. 
Published: February 2005

AbstractBetween weaning and adulthood, the length and height of the facial skull of the New Zealand rabbit (Oryctolagus cuniculus) double, whereas much less growth occurs in the width of the face and in the neurocranium. There is a five‐fold increase in mass of the masticatory muscles, caused mainly by growth in cross‐sectional area. The share of the superficial masseter in the total mass increases at the cost of the jaw openers. There are changes in the direction of the working lines of a few muscles. A 3‐dimensional mechanical model was used to predict bite forces at different mandibular positions. It shows that young rabbits are able to generate large bite forces at a wider range of mandibular positions than adults and that the forces are directed more vertically. In young and adult animals, the masticatory muscles differ from each other with respect to the degree of gape at which optimum sarcomere length is reached. Consequently, bite force can be maintained over a range of gapes, larger than predicted on basis of individual length—tension curves. Despite the considerable changes in skull shape and concurrent changes in the jaw muscles, the direction of the resultant force of the closing muscles and its mechanical advantage remain stable during growth. Observed phenomena suggest that during development the possibilities for generation of large bite forces are increased at the cost of a restriction of the range of jaw excursion.
The exocrine glands of Dysdercus cingulatus (Heteroptera, Pyrrhocoridae): Morphology and function of nymphal glands
Authors: Farine Jean‐Pierre 
Published: February 2005

AbstractThe exocrine glandular system of the nymphs and the adults of Dysdercus cingulatus were studied. The D. cingulatus nymphs present 3 dorso‐abdominal glands (lying under the 3rd, 4th, and 5th abdominal terga) and a pair of dorso‐lateral pygidial glands on the pygidium (tergum 8). Histological and ultrastructural studies show that the upper and lower walls of the dorso‐abdominal glands differ in structure; 3 types of cells were described: epidermal cells, unicellular secretory cells, and multicellular secretory units. Each of these exocrine glands plays an important part in the behavior of the nymphs (gregariousness, alarm, defense). The morphology of the various glands is discussed, and the chemistry of their secretions and their biological functions are considered.
TheJournal of morphologyas window and mirror: Reflections and glimpses on the birth of american biology
Authors: Benson Keith R. 
Published: February 2005

AbstractThe centennial of theJournal of Morphologyprovides a fitting occasion to reflect upon the condition of American biology surrounding the founding years of theJournal.TheJournalwas started by C.O. Whitman in 1887. At this same time, the American biological community experienced a gradual change from a community of amateurs based within the natural history tradition to a professional community based within universities with specialized research programs. Many of the changes associated with this maturation process are exhibited in the pages of the first ten volumes of theJournal.They show that theJournalplayed a central role in communicating research methods and questions to the growing community of professional biologists. Moreover, these same volumes provide an accurate record of the character of the morphological sciences at the end of the 19th century.
Functional mechanisms and histologic composition of the lingual appendage in the alligator snapping turtle, Macroclemys temmincki (Troost) (Testudines: Chelydridae)
Authors: Spindel Edward L. , Dobie James L. , Buxton Donald F. 
Published: February 2005

AbstractGross and microscopic examination of the lingual appendages of juvenile and adult alligator snapping turtles, Macroclemys temmincki, shows that it is divided into an anterior horn, a body, and a posterior horn. Lingual appendages of adults usually are more darkly pigmented than those of juveniles and melanocyte distribution is variable, resulting in a mottled appearance. The musculoskeletal components of the hyoid apparatus, presumably responsible for most of the motion displayed by the appendage, are described here. The lingual appendage is innervated by the lingual nerve which divides into three branches, two coursing rostrally into the anterior horn and one running caudally into the posterior horn. These branches ramify and end in numerous terminals within the lamina epithelialis and lamina propria. The lamina epithelialis of the distal three‐fourths of the horns of the lingual appendage contain structures similar to taste buds described in other species of turtles. Goblet cells, containing acid mucopolysaccharides, are located in the stratified squamous epithelium. Blood is transported to the appendage via the lingual artery, which is a terminal branch of the external carotid artery. Numerous venous sinuses lie among the predominant bundles of connective tissue and account for approximately one‐fifth of the total volume of the appendage. An engorged appendage is swollen and pinker in color.The coloration, enlargement, and wiggling movement combined with its buoyancy in water make the appendage imitate a small worm or an insect larva. The increase in melanin during ontogeny may produce a more variable pattern and may increase the number of organisms attracted by the appendage. The acid mucopolysaccharides of the globlet cells presumably may condition the nonkeratinized, stratified squamous epithelial surface of the appendage. The flexibility of the pseudoerect, active appendage keep it from being injured.
Gross and ultrastructural development of the saccule of the toadfish Opsanus tau
Authors: Sokolowski Bernd H. A. , Popper Arthur N. 
Published: February 2005

AbstractThe development of the saccule of the inner ear in the toadfish was studied using light and scanning electron microscopy. Development was studied from the early embryo (2–3 days postfertilization), when the otocyst first forms, to the early‐aged juvenile when the development of the inner ear approximates that of the adult (4 weeks postfertilization). The ultrastructural features examined included the morphological sequence of ciliary bundle growth, the development of orientation patterns of the ciliary bundles, and the relation of the ultrastructural development to overall gross development.Gross development may be divided into four distinct morphological stages. Stage I encompasses the time from initial formation of the otocyst until the start of stage II, which is the stage when the pars inferior begins migrating ventrally. In stage III the pars inferior continues to elongate ventrally. Stage IV starts when the pars inferior elongates in a rostral and caudal direction. The ear attains its adult shape in stage IV.The differentiation of the sensory cells begins during stage I. During the early part of stage I, a small cilium is found on the apical surface of each cell throughout the otocyst. In the middle and late periods of stage I, a few micro—villous buds add to the surface of the cells that already have a kinocilium. These early ciliary bundles are clustered on the rostral—ventral and caudal walls of the otocyst. There is no clear patterning to the orientation of these ciliary bundles. In stage II the ventral stretching of the labyrinth wall causes a spreading of the clustered bundles along the ventral and medial walls of the pars inferior. The orientation of the ciliary bundles has no distinct pattern. In stage III the orientations of the ciliary bundles appear adultlike, although there are so few ciliary bundles that it is difficult to make a definite determination. During stage IV, hair cells with an adultlike horizontal and vertical orientation pattern are found on the rostral and caudal sections of the saccular macula, respectively. The transition region lying between these areas has ciliary bundles with various orientations.
Morphology of the oral disc of Bufo bufo (Salientia: Bufonidae) tadpoles
Authors: Marinelli M. , Vagnetti D. 
Published: February 2005

AbstractThe fully developed oral disc of the tadpole of Bufo bufo consists of dorsal and ventral labia bearing, respectively, two and three ridges bearing numerous horny denticles, a horny beak provided with jaw sheath serrations, and large lateral papillae that are borne by two cutaneous plicae. As development progresses toward metamorphosis, these structures gradually regress until they disappear. Each cusped clavate labial denticle adheres, by means of a thin peduncle, to a similar labial denticle fixed in the lip and formed by a group of three or four cells that keratinize gradually and thus present remarkable differences in their morphology. Once all the cells of a group have been converted into horny tissue, the denticle sheds and is replaced by the underlying one. The beak serrations also are horny structures; each consists of a columnar band of cells which undergoes a gradual keratinization. The horny cells that detach themselves at intervals, being replaced by those of the underlying anlagen. The labial denticles and the beak serrations keratinize in two distinct ways. In the former, the desmosomal filaments appear to play an important role whereas, in the latter, the keratin seems to be synthesized “ex novo” by the ribosomes.