bluuebunny/crossref_metadata_2025_split huggingface dataset:
The development of the posterior cardinal veins in relation to the swim bladder in Lepidosteus
Authors: Potter George E. , Self J. Teague 
Published: February 2005

AbstractThe origin and development of the posterior cardinals and associated veins in relation to the swim bladder, as well as their morphology, have been studied in Lepidosteus. The posterior cardinals develop, beginning in the 4‐mm. stage, as sinuses in the mesenchyme dorsal to the gut and near the mesonephori. A pneumatic vein appears first in the 13‐mm. stage. It collects from the posterior portion of the swim bladder and empties into the right posterior cardinal. In the younger stages the caudal vein empties directly into the posterior cardinals as is the case in the adult cyclostome, but by the 58‐mm. stage it has joined veins dorsal to the mesonephori forming a renal portal system. An anal vein appears in the region of the anus and joins the caudal. Later, with the development of the renal portal system, the anal separates from the caudal to become the single posterior extension of the posterior cardinals. The posterior portion of the right cardinal contributes largely to the development of an abdominal portal vein extending from the posterior root of the right posterior cardinal to the liver. These relationships of the posterior cardinals differ from those found in other fishes, due perhaps to the function of the right cardinal and its pneumatic branch in collecting blood from the swim bladder.
The material continuity and individuality of the somatic chromosomes of Ambystoma tigrinum, with special reference to the nucleolus as a chromosomal component
Authors: Dearing William H. 
Published: February 2005

AbstractTwo features of this study have furnished direct evidence for the material continuity and individuality of the chromosomes in the epithelial cells of the larvae of Ambystoma tigrinum (1) the tracing of the complete history of a specific chromosome, the nucleolus‐containing chromosome, throughout the successive stages of mitosis and interkinesis, (2) the following of the exact parallelism in behavior (during mitosis) of the chromosomes in a given nuclear group with that in a single chromosome which has been isolated in the cytoplasm from the main chromosomal complex.Each of the two nucleoli is subterminally located in the short arm of one of two particular V‐shaped chromosomes. The latter are probably homologues.78: In this subterminal chromosomal position the nucleolus exhibits in fixed and stained preparations an achromatic character in late prophase, metaphase, anaphase and early telophase, while it presents itself as a chromatic element in middle telophase, late telophase, interkinesis and early prophase.The nucleolus is not a simple homogeneous body, but rather a complex structure, the nature of which is revealed in the study of its evolution during the chromatic phase of its cycle in mitosis.
Measurements of the skull and of some of the long bones of the muskrat (Ondatra zibethicus cinnamominus)
Authors: Latimer Homer B. , Riley Ray B. 
Published: February 2005

AbstractThe skull, mandible, and five pairs of long bones from the skeletons of 125 muskrats were weighed and measured. Each bone of the pairs of long bones was weighed and measured separately. Thirteen dimensions of the skull were determined.The long bones are slightly less variable in length than the skull dimensions. There is a rather wide range of variation in the thirteen dimensions of the skull, with the length and breadth of the skull less variable than the lengths of the long bones.The coefficients of correlation show that the weight of the skull is a good index to the weights of the long bones. The skull length has likewise high correlations with the lengths of the long bones and the longitudinal dimensions of the skull, with the exception of the palatine slits. The transverse diameters are not significantly correlated with the skull length.The long bones are asymmetrical in weight and length. They are longer more frequently on the left side and all except the tibia are heavier more frequently on the left side.
A study of the development of the cochlea and cochlearis in the fetal albino rat
Authors: McRoberts Donald D. 
Published: February 2005

AbstractThe position of the inner ear and its relation to surrounding structures in the fetal head is ascertained. The growth and shape change of the cochlea is followed and measured. The change in size and appearance of the ductus cochlearis has been followed througout the various fetal stages. The growth and development of the scala vestibuli and scala tympani have been noted. The size and shape of the cells of the organs of Corti and the development and attachments of the tectorial membrane have been measured. The growth and developmental relationships of the tunnel of Corti have been followed. The growth and time of appearance of the organs with their relationship to hearing have been treated. The type of cell structure and the various structural changes throughout the development have been noted and correlated with the growth and size of the structure as a whole. The repidity of growth of all separate parts has been correlated and united to show the extent of development of the newborn rat inner ear.
A study of the spermatozoon of the fowl, with particular reference to osmiophilic bodies in the sperm head
Authors: Adamstone F. B. , Card L. E. 
Published: February 2005

AbstractThe purpose of this study was to learn something of the nature of the bead‐like bodies which occur in the head of the sperm of the fowl since it was found in a previous study that they are apparently affected in a characteristic manner by vitamin E deficiency.Staining tests indicate that these bodies are composed of fats and fatty acids since they respond to osmic acid and Nile blue sulphate. They are also impregnated with silver nitrate and hence may be associated with the so‐called Golgi materials of the cell.The beads first appear as a complete single row but subsequently they undergo fragmentation and redistribution. The whole process is probably a final transitory step in sperm transformation.The presence of this fatty material may signify that the sperm of the fowl, in contrast to that of most other animals, carries a store of food material to support its activity after liberation. The sperm may also be the carrier of a definite amount of vitamin E. Furthermore, the presence of this material may offer an explanation of the high resistance of the testis of the fowl to vitamin E deficiency because, since this vitamin is fat soluble, the testis as a whole would probably receive a disproportionately large share of the vitamin E stores of the individual.
On the arterial system of the common Indian rat‐snake, Ptyas mucosus (Linn.)
Authors: Ray Harish Chandra 
Published: February 2005

AbstractThe arterial system of Ptyas mucosus (Linn.) reveals the following interesting features: (1) A prominent diverticulum given off from the inner antero‐dorsal edge of the left auricle. (2) Ridge‐like continuation of the median hanging valve of the sinus venosus lining the ventral edge of the opening of the right precaval vein. (3) Guarding of the opening of the pulmonary vein by a portion of the inter‐auricular septum abutting against it. (4) Presence of two longitudinal trunks on either side of the hepatic portal vein formed by the hepatic branches of the hepato‐oesophageal arteries, which, uniting with one another, form a peculiar arrangement looking almost like a looped chain. (5) A complete arterial circuit in the female formed by the combination of the genital, supra‐renal, and the anterior‐most renal arteries of either side. (6) Chain‐like arrangement formed by the alternate bifurcation and union of the posterior‐most part of the longitudinal fat‐body artery and also by its lateral branches, which unite with it here and there after giving off twigs to the fat bodies. (7) A pair of small arteries (or in some cases only one) called ‘arteria complexa’ which take their origin from the dorsal aorta opposite the openings of the iliac veins into the afferent renals.
Insect development. VII. Early stages in the development of grasshopper eggs of known age and with a known temperature history
Authors: Slifer Eleanor H. , King Robert L. 
Published: February 2005

AbstractThe rate of maturation and of development during the first 4 days has been followed in Melanoplus differentialis eggs (from mated females) collected (1) just before they were laid, or (2) immediately after oviposition had been completed and (1) either fixed at once, or (2) after incubation at 25°C. for definite periods.
The early development of the thymus glands in amia calva
Authors: Hill Benjamin Harvey 
Published: February 2005

AbstractThree pairs of thymus primordia are found at 6 to 6.5 mm. on the dorsal lateral ends of the second, third and fourth visceral pouches. Those on each side after fusing by growth and migratin come to lie above the third visceral pouch, whence the thymus migrates upward and backward; growing in size, it stretches above the ends of all the gill pouches. It pushes inward into the mesenchyme at 12 to 13 mm. and becomes perforated and surrounded by blood vessels and connective tissue which separate it almost completely from the epithelium. No septa are found; occasionally the third primordium fails to fuse and forms a separate lobe.The early thymus is a syncytium in which are found lymphoblasts, identified by structure of the cytosome and its behavior during mitosis. Evidence is presented that lymphoblasts migrate into the thymus where they increase in number with corresponding increase in length of cytoplasmic bridges and size of intercellular spaces. At 10 mm. begins a rapid increase in size of the thymus and in number of lymphoblasts and decrease in size of the latter, culminating at 12 to 13 mm. in their transformation into thymocytes. A medulla associated with blood vessels is unmistakable at 30 mm.
The chitinous structures in the posterior abdominal segments of certain female termites
Authors: Browman Ludvig G. 
Published: February 2005

AbstractThe external genitalia of female termites are readily homologized with those of female roaches. Mastotermes and other representative termites from every family are compared and their phylogenetic relationships within the group are found to agree, with the exception of the Hodotermitidae, with those based on studies of other structures.
Organography of Gambusia patruelis (baird and girard)
Authors: Potter George E. , Medlen Ammon B. 
Published: February 2005

AbstractThe left side of the coelom of the fish is occupied by the large liver and the right side by the remaining digestive organs. The alimentary tract makes one complete coil upon itself in the coelom and terminates in an anus behind the ventral fin. The spleen is in a position dorsolateral to the liver, and its typical histological structure is modified by the presence of pancreatic tissue. The pancreas is scattered through the mesenteries of the organs in this region.The swim bladder is dorsal to the visceral organs and outside of the abdominal peritoneum. It is extensively bifurcated in the male, but only slightly bifurcated in the female.The two kidneys lie posterior to the gills and ventral to the spinal column. Two wolffian ducts arise from their posterior ends and extend posteriorly, uniting near the end of the coelom to form one duct which extends to the urinary bladder which opens into the urogenital sinus.The gonads are posterior to the anterior portion of the digestive tract. Posteriorly, the gonads open into the urogenital sinus which opens anterior to the anal fin.The anatomy of the circulatory system is unusual in that the dorsal aorta is situated on the left side of the spinal column. The right posterior cardinal vein remains as the continuation of the caudal vein.
Cytological studies of the Chilomastix (protozoa, flagellata) of man and other mammals
Authors: Geiman Quentin M. 
Published: February 2005

AbstractAccounts of binary fission for two species of Chilomastix by Bélar ('21) and Boeck and Tanable ('26) differ. Consequently, investigations were initiated to study the cytology and to determine the nature of binary filssion in Chilomastix mesnili of man, Chilomastix mesnili (?) of anthropoid apes and monkeys, and Chilomastix intestinalis of guinea pigs.The material used for the study included the following: four heavily infected human cases of Chilomastix mesnili, twenty‐one infections of Chilomastix mesnili (?) from a survey of thirty‐six anthropoid apes and monkeys at the Philadelphia Zoölogical Gardens, and Chilomastix intestinalis from six guinea pigs.The results of the investigations indicate that binary fission of the above three species of Chilomastix are similar in essential details. Encystment is described for the species from man and from anthropoid apes and monkeys. No evidence for mitosis within the cysts was obtained for C. mesnili of man. In C. mesnili (?) from primates other than man, the appearance of cyst nuclei resembling mitotic processes is explained as variations occurring in nuclei. Binucleate cysts are believed to be formed by the encystment of abnormal binucleate individuals which never had undergone plasmotomy after division of the nuclei.
The development of the anterior post‐otic somites in the rabbit
Authors: Hunter Ruth MacMillan 
Published: February 2005

AbstractA study is presented of the most anterior postotic somites in a series of embryos from the five‐somite stage to 16 days. A gradual fading out of the somite forming tendency in this region seems to be indicated both by the formation of a rudimentary somite and by conditions found in the first true somites.There are, in the rabbit, three occipital somites, all of which form myotomes. The fate of the myotomes is traced until their identity is lost in the formation of definitive muscle masses.From the sclerotomes two occipital arches, comparable to those of vertebrae, are formed and can be identified as late as the time of beginning chondrification. There is a marked compression of the tissues in this region, the sclerotomal material being not only relatively but actually shorter in older embryos. This compression results in, 1) the approximation of the hypoglossal roots, and, 2) the fusion of the two occipital arches.The cartilaginous basal plate in rabbits begins development at its caudal end and differentiates anteriorly from this with little evidence of a primitive segmentation except as this posterior first center might be called a segment.
The formation of shell in the tiger snail
Authors: Jones David T. 
Published: February 2005

AbstractThis article describes the structural features of the mantle and shell, particularly in the tiger snail, Anguispira alternata. The shell and the slime appear to be secreted simultaneously, probably from the same sources, and except for the mucus probably from the same materials, but certainly through very different structures.It is found that all the layers of the shell are secreted in a liquid or semi‐liquid state by some part of the mantle. The periostracum is secreted from the supramarginal groove as a liquid which soon toughens as viscosity increases until it forms the organic covering of the shell. The inner layers are derived from epithelia beneath the shell, crystallizing out of a semi‐liquid mass into the characteristic patterns, which we recognize as the layers of calcium carbonate. This process is traced from the synthetic viewpoint in the secretion from the mantle, also some of the stages can be detected from the analytic standpoint in the breakdown of shell materials.Some phases of the above structural states can be recognized in living mantles. A chemical analysis of the shell is also given.
The development of the thyroid gland in urodeles
Authors: Sanders James M. 
Published: February 2005

AbstractThe development of the thyroid has been briefly described from an example of each of the four urodele families and comparisons drawn. An attempt has been made toward clarifying previous and conflicting accounts. The thyroid arises as a solid bud from the floor of the pharynx in the region of the first visceral pouches. This bud grows backward until it reaches the pericardium. Division of the primordium into lateral portions is inaugurated and the anterior end of the splitting thyroid loses its connection with the pharynx before the separation of the parts is completed. Some of the undivided anterior portion may persist as an accessory thryroid. After the two lateral thyroid masses are separated the yolk disappears from the cells which then form cell columns and enlarge as a result of the fusion of adjacent vesicles. A thyroid [release] occurs at the time of metamorphosis except in Necturus. After the [release] the follicles refill. Similarities in development and general histological picture are closer between Necturus and Cryptobranchus as a pair than between either of these forms and Amblystoma or Eurycea. Amblystoma and Eurycea also resemble each other in histological picture. It is suggested that Necturus produces the thyroid hormone in sufficient quantity to induce metamorphosis but that some other factor or factors serve to inhibit the response.
The role of muscular contraction in the production of configurations in the insect skeleton
Authors: Maloeuf N. S. Royston 
Published: February 2005

AbstractExtensive measurements were made on skeletal configurations and muscles of several forms of Hemiptera‐Homoptera from the early nymphal instars to the adults, inclusive. It has been shown that several of the muscles actually decrease in length (i.e., contract) as the animal grows as a whole. Such a state of affairs has never before been observed, so far as the writer knows. The most marked increase in length of a skeletal invagination often coincides with the greatest amount of contracture of the muscle which is attached to its extremity. The characteristics of the arthropod skeleton, which consist of invaginations and evaginations are probably, in the forms studied, due to muscular contraction or to the prolonged sustenance of muscular tonicity.The form of muscular contraction described probably belongs to the ‘catch’ type rather than to the metabolic type. The direct cause of these muscular contractions is probably due to changes in physico‐chemical constitution of the haemolymph.
The slit sense organs of spiders
Authors: Kaston Benjamin Julian 
Published: February 2005

AbstractAlthough there has been much dispute in the past concerning the structure and function of the slit sense organs it is highly probable that they are chemoreceptors somewhat analogous to the pore‐plate organs on the antennae of insects. The cuticular portion of a compound organ is made up of a number of more or less parallel slits in the outer cuticula. These slits are separated by thick laminae arranged as in a grid. A thin epicuticular membrane covers both laminae and slits between, while a thinner membrane is present at the inner ends of the slits. The hypodermal portion is composed of tall cells with a granular basal and a fibrillar distal cytoplasm. The sense cells are typical bipolar neurones, one for each slit of the organ. The distal sensory fiber traverses the fluid filled slit and ends at the epicuticula. It is never exposed directly to the outside. The structure of single slits is essentially similar to that of compound organs. In accordance with Schenk's well‐known system of nomenclature for analogous structures in insects the term sensilla tomosa is suggested for both. The results of this study in fifteen species from nine families indicate that these organs are the same in all spiders, and that they are adapted for the function of chemoperception.
Some muscular changes in the tail and thigh of reptiles and mammals
Authors: Haines R. Wheeler 
Published: February 2005

AbstractNew dissections of the caudal and short posterior thigh muscles of the reptiles Iguana, Varanus, Crocodilus and Testudo, and the mammals Sciurus, Galago and Herpestes were made, and the findings correlated with those described in the literature. The condition in the lizards, Sphenodon and crocodiles is very constant; in each case there is a puboischiofemoralis externus and an ischiotrochantericus passing from the pelvis to the femur, a deep caudal mass passing from the tail to the femur, and a superficial caudal sheet attached to the ilium and ischium. In the Chelonia, with the specialization of the gait, the deep caudal musculature has lost its attachment to the femur, and has migrated onto the vertebral column and the inner surface of the pelvis, while the other muscles occupy their typical position. In the Mammalia the deep caudal musculature has undergone a change similar to that in the Chelonia, forming the pubo‐, ilio‐, sacro‐ and ischiococcygeus muscles, while the superficial caudal musculature has disappeared except for a part which forms a sphincter cloacae. The posterior part of the puboischiofemoralis externus has formed the quadratus femoris, and the ischiotrochantericus the obturator internus and the two gemelli. In specialized mammals with reduced tails the caudal musculature has taken over new functions and become respecialized in different ways.
A study of the reappearance of melanophores and the formation of melanophore aggregations (spots) in regenerated ventral skin of the common newt, triturus viridescens
Authors: Apgar Bessie Dickerson 
Published: February 2005

AbstractStudies of regeneration in a denuded area 3 to 5 mm. square made by dissecting away the epidermis and underlying dermis were carried out both in the living animal and with the aid of histological sections. During the reconstitution of the area pigmented cells appeared in the new epidermis. There was no evidence that they wandered in from the surrounding epidermis. They developed in situ and most of them later disappeared. In the deeper tissues of the regenerating area, pigmented cells appeared in localized areas which gradually increased in size and density of color and formed typical black spots. These remained permanently.If the incision passed through or close to an original spot there was migration of melanophores into the adjacent territory and the subsequent formation of a spot. All other new spots were formed from melanophores which appeared in situ, by the formation of pigment in cells which had previously been unpigmented.
A study of mistichthys luzonensis with special reference to conditions correlated with reduced size
Authors: Te Winkel Lois E. 
Published: February 2005

AbstractA histological study has been made of the developing mid‐gut or mesenteron of Melanoplus differentialis from diapause until after hatching. The primitive mid‐gut consists at first of a single layer of squamous epithelium surrounding the yolk; to this is added later an outer layer. These two layers give rise to the muscular and connective tissue elements of the definitive mid‐gut. Near the time of hatching, vitellophages which have been present in the yolk since earlier stages migrate peripherally to form a lining upon the inner surface of the primitive mid‐gut. The vitellophage nuclei divide to form the smaller nuclei of the definitive epithelium of the mid‐gut. The development of the definitive mesenteron from the primitive mid‐gut takes place rapidly and occurs near the time of hatching.