bluuebunny/crossref_metadata_2025 huggingface dataset:
The blood cells of the trematode diplodiscus temperatus
Authors: Jordan H. E. , Reynolds B. D.
Published: February 2005

The vascular channels and sinuses of this trematode contain three varieties of cells: eosinophilic granulocytes, primitive hemocytoblasts (‘amebocytes’), and modified hemocytoblasts. The latter suggest a specialized blood corpuscle, but represent apparently only a stage in the dissolution of intravascular hemocytoblasts. These ‘corpuscles’ have the form of flattened lenticular discs, approximately 12 μ in diameter. The eosinophils differentiate extravascularly from hemocytoblasts. The hemocytoblasts are in part free parenchymal cells, in part they arise from a bilaterally paired ‘lymphogenous organ’ or ‘blood island’ associated with the lateral vascular channels at the level where the ceca diverge from the esophagus.
Some ultraviolet photomicrographs made with different wave lengths
Authors: Wyckoff Ralph W. G. , Ebeling Albert H.
Published: February 2005

Photomicrographs have been made of grasshopper spermatocytes using ultraviolet light of several wave lengths. For studying chromosomes this wave length should be between ca 2800 A and ca 2500 A. With higher frequencies the entire cell becomes strongly absorbing and relatively little detail is to be seen. All cell structures, including the chromosomes, are as transparent to λ = 3500 A and to longer ultraviolet waves as they are to visible light. The present experiments do not indicate the exact point between λ = 3500 A and λ = 2800 A at which the selective chromatin absorption commences.
Studies on the morphology of tritrichomonas foetus (Riedmüller) (protozoa, flagellata) from American cows
Authors: Wenrich D. H. , Emmerson M. A.
Published: February 2005

Tritrichomonas foetus (Riedmüller) which occurs in the genital tract of domestic cows and which appears to be associated with pathological conditions, including sterility and abortion, has been found in American cows and its morphology studied.

The spindle‐shaped body is 10 to 25 μ in length and bears three anterior flagella and a posterior flagellum which constitutes the marginal filament of the nearly full‐length undulating membrane and continues posteriorly as a trailing flagellum. There is an accessory filament in the undulating membrane. The axostyle is of the thick, hyaline type and contains endoaxostylar granules in the capitulum and bears a chromatic ring at the point of emergence from the body. There is a well‐developed costa under the undulating membrane and a simple type of parabasal body.

In its morphology this species more nearly resembles such intestinal forms as T. augusta and T. muris than it does Trichomonas vaginalis of man, since the latter has four anterior flagella, a short undulating membrane without an accessory filament, no trailing flagellum, a different type of axostyle, and a parabasal filament along with its larger parabasal body.
The effect of x‐rays upon the chromosomes of circotettix verruculatus (orthoptera)
Authors: Helwig Edwin R.
Published: February 2005

X‐rays produce fragmentations of the chromosome commonly in the region of fiber attachment.

Fiberless fragments become attached to other chromosomes or those portions of them that retain fiber attachments. Thus, chromosomes homologous to parts of two other chromosomes are produced and at synapsis multiples are formed. Such multiples are chains or closed‐circles depending upon whether a single or a reciprocal translocation respectively has occurred. Sometimes entire chromosomes unite to form a multiple. In general, the multiples divide so that the segregation of homologous elements is complete. However, sometimes the separation of homologous portions is impossible and, then, gametes which contain sectional‐duplications, or sectional‐deficiencies, or both, are produced. Any two or more chromosomes may be involved in multiple formation although the larger elements are more frequently implicated.

Translocations may occur between homologues resulting in an unequal division of chromatin.

The locus of fiber attachment (acromite) is an integral part of a chromosome and its loss to one homologue causes non‐disjunction or other inequalities in the distribution of the chromatin.

Supernumerary chromosomes are frequently present in the spermatocytes.

Homologues unaccountably sometimes fail to synapse in the descendants of irradiated cells.

There is a striking similarity between natural and induced chromosomal aberrations as well as a correlation between the distribution of radioactive minerals and naturally occurring aberrations.
Chromosome studies in stauroderus (an orthopteron)
Authors: Corey H. Irene
Published: February 2005

S. scalaris (Orthoptera, Truxalinae) from Scotland and Siberia has a diploid complex of seventeen chromosomes (six V‐multiples and eleven rods). Each element possesses a polar or proximal granule recognizable throughout all stages of prophase of the first spermatocyte and in all other stages when concentration is not so great as to mask it. In telophase of the first spermatogonial division the polar granules may fuse into a single body or into several irregular bodies (chromoplasts of Eisen and Janssens). By the end of the diatene stage the chromoplast is completely resolved into its component granules which are clearly recognizable as the proximal parts of the rods (ends) and of the multiples (mid‐portions). The accessory chromosome is precocious in its behavior and differential in structure at all stages, but its peculiarities are most marked in metaphase of the first spermatocyte where it becomes a non‐chromatic vesicle with peripheral granules and chromatic core. Each multiple arises from the permanent fusion of two rod elements. They differ from those in other members of the same sub‐family in diakinesis (eight‐strand or octad stage) in that proximal concentration extends almost throughout the multiple.
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

The 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

Two 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

The 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

The 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

The 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

The 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

The 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

Three 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

The 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

The 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

Accounts 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

A 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

This 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

The 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

Extensive 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

Although 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

New 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

Studies 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

A 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.
The primordial germ cells of the chick I. the effect on the gonad of complete and partial removal of the ‘germinal crescent’ and of removal of other parts of the blastodisc
Authors: Goldsmith Joseph B.
Published: February 2005

The ‘germinal crescent’ of the primitive streak stage chick embryo is located in the zone of junction anterior and lateral to the proamnion. The primordial germ cells supposedly arise from this area.

The following experiments were carried out. 1. Complete removal of the germinal crescent. 2. Partial removal of the germinal crescent. 3. Removal of areas of corresponding size of the blastodisc other than the germinal crescent.

The results are as follows: In experiment 1, a careful search of the entire specimen failed to reveal any primordial germ cells. Such embryos invariably died during or before the fifth day of incubation.

In experiments 2 and 3, the presence of the primordial germ cells was quite obvious. Such embryos did not invariably die. Some from each group was brought through to hatching, with the exception of that group in which the piece was taken from the lateral region of the blastodisc. In this case the injury to the circulation was too great to overcome.

As was to be expected, in those specimens in which the circulatory system was injured rather severely death always ensued and occurred before the third day of incubation regardless of the type of experiment.

Both cauterization and removal with scissors were tried. Mechanical removal gave superior results and was used exclusively in the latter part of the experiment.
The contractile vacuole of paramecium multimicronucleata
Authors: King Robert L.
Published: February 2005

Each contractile vacuole system of Paramecium multimicronucleata is made up of a number of components, some temporary and others permanent. The contracting vacuole with its membrane is a temporary structure as are the vesicles which fuse to form it. The vacuole discharges its contents to the exterior leaving a vestige closing the pore. The pore, with its discharging tubule and the feeding canals are permanent cell organelles. The feeding canals end in injection tubules which extend up to the pore. The vesicles, which later fuse to form the vacuole, are formed at the proximal end of the injection canals, leaving a membrane closing the canal, much as a food vacuole is formed at the gullet. The canal‐fed contractile vacuole of Paramecium is very similar to the vesicle‐fed vacuole of Euplotes both as to its origin and its fate. The Nassonov homology is rejected.
The chromosomes of cryptobranchus allegheniensis
Authors: Makino Sajiro
Published: February 2005

The number and behavior of the chromosomes have been investigated in the spermatogenesis of Cryptobranchus allegheniensis. The spermatogonium contains sixty‐two chromosomes, which are composed of twelve atelomitic V‐shaped ones, and eighteen long and thirty‐two short telomitic ones. The haploid number of chromosomes is ascertained to be thirty‐one in both of the primary and secondary spermatocytes.

The chromosomal relation between the present species and Megalobatrachus japonicus, a closely related form, has been discussed.
The intergeneric homology of an atypical euchromosome in several closely related Acridinae (order orthoptera)
Authors: Carlson J. Gordon
Published: February 2005

An atypical euchromosome, characterized by the large size and deep stainability of its chromomeres during the meiotic prophase, occurs in representatives of seven genera of Acridinae, viz., Chorthippus curtipennis, Euchorthippus pulvinatus, Stenobothrus lineatus, Omocestus ventralis, Stauroderus biguttulus, Gomphocerus rufus, and Aeropedellus clavatus. This element, which is termed the ‘megameric chromosome,’ stains more deeply than the other euchromosomes also during interkinesis and early spermiogenesis. The megameric chromosomes of the individual exhibit striking similarity in the number, size, and arrangement of their chromomeres through successive stages of the meiotic prophase. All the evidence from cytological study indicates that these chromosomes are intergenerically homologous. This is chiefly significant in the support it gives to the theory of chromosome individuality. The heteromorphic megameric tetrad of one individual of S. biguttulus—unequal because of a deficiency—usually undergoes segregation in the second division. The megameric chromosomes display splits previous to synapsis. Pairing begins at their proximal ends and proceeds distally. All the euchromosomes of the spermatid nucleus show splits in preparation for the first cleavage division of the zygote.
The origin of new epidermal cells in the skin of normal and x‐rayed frogs
Authors: Cameron John Andrew
Published: February 2005

The skins of normal and x‐rayed tadpoles and frogs were compared. Almost no mitotic figures occurred after the tenth day of larval life. The number of mitoses and the length of the period during which mitosis occurred were reduced by x‐rays in proportion to the exposure. Spindle‐shaped cells were found on the vertical connective tissue fiber bundles which connect the lower layer of the dermis with the under side of the epidermis in adult frogs. After exposure to 4000 r the number of these cells, which are believed to be traveling up the vertical strands to join the epidermis, was doubled. New, uninjured cells appeared in the basal epidermal layer following this increase. Since no appreciable number of mitotic divisions and no amitotic divisions were found in the epidermis, either normally or during the regeneration following exposure to x‐rays, these ‘traveling‐cells’ are held to be an important source of replacement in correlation with normal desquamation as well as desquamation caused by the irradiation.
The metamorphosis of Drosophila melanogaster, including an accurately timed account of the principal morphological changes
Authors: Robertson Charles William
Published: February 2005

During the quiescent fourth larval instar the larva of Drosophila becomes loosened from the puparium and takes on the form of a pupa. A large gas bubble is formed within the body during this prepupal period. At the end of this stadium, which lasts 11 1/2 hours at 25°C., it pupates, shedding the prepupal cuticle. The gas bubble is used as a mechanism to separate the cuticie from its hypodermis. Practically all of the tissues undergo histolysis and are replaced by imaginal structures derived from specialized cells. Some of the muscles persist longer than the general mass and perform special functions in the pupa. The sequence of histolytic and histogenetic changes is accurately timed at a constant temperature.
The effect of fat extraction on Golgi bodies of kidney cells of the frog
Authors: Eastlick Herbert L.
Published: February 2005

Frog kidney, when fixed in 4 per cent formalin and subsequently treated with Kolatchev solutions, is found to contain osmiophilic bodies which not only appear identical to the Golgi substance of Kolatchev fixed controls but which also resist bleaching in hydrogen peroxide or potassium permanganate solutions. If a formalin fixed kidney is dehydrated and extracted with various fat solvents and subsequently fixed with the Kolatchev technique, Golgi bodies are usually completely removed but occasionally cells are found which contain spherical globules of osmiophilic substance scattered through the cytoplasm.

Kidney tissue fixed in a mixture of 95 parts of alcohol plus 5 parts of formalin before application of the Kolatchev solutions does not contain Golgi bodies. The same results are obtained if benzene is used instead of alcohol and formalin. Striated muscle, when treated in a similar manner, contains darkly stained (Z) and (M) membranes, therefore the osmophilic substance present in muscle quite widely daerent, chemically and physically from that contained in kidney cells.

It is apparently an established fact that formalin preserves phospholipids in tissues nnd this investigation has shown that Golgi bodies in kidney cells can be demonstrated following fixation in formalin. Moreover, the Golgi bodies, which are preserved by formalin, can be removed by extracting the tissue with fat solvents. This evidence, therefore, strengthens the hypothesis that true Golgi substance is phospholipid in nature.
On the venous system of the common Indian rat‐snake ptyas mucosus (Linn.)
Authors: Ray Harish Chandra
Published: February 2005

The venous system of Ptyas mucosus (Linn.) presents the following features which appear to be hitherto undescribed in Ophidia: (1) Direct connection of the anterior azygos vein with the lateral cephalic vein just behind the head and also its anastomosis with either of the common jugular veins (right or left). (2) Anastomosis of the right and left common jugular veins with the epigastric vein in the neck region. (3) Left common jugular vein larger than the right. (4) Origin of the oviducal sinuses directly from the afferent renal veins and their termination on either side directly into the postcaval. (5) Persistence of the posterior cardinal veins in both the sexes. (6) Opening of most of the branches of the epigastric vein directly into the vena mesenterica in the liver region and of a few only into the right lobe of the liver. (7) Branches from the meso‐rectum contributing to the formation of the vena mesenterica. (8) Opening of some veins into a branch of the epigastric vein lying just behind the heart, which carry blood from the dorsal surface of the right lung, trachea, pericardial wall, and also from the parietal layer of the body wall on the left side.
The cytological changes in the hypophysis cerebri of the garter snake (Thamnophis radix) following thyroidectomy
Authors: Siler Kenneth A.
Published: February 2005

Changes in the hypophysis cerebri of the garter snake, Thamnophis radix radix Baird and Gerard, were found in the anterior lobe of the nineteen thyroidectomized animals reported. Chromophobic cells enlarge and acquire a basophilic granulation, to become apparently normal beta (basophilic) cells. These, along with the beta cells originally present, become vacuolated, lose their granular content, apparently by liquefaction of the granules, and finally degenerate. The hypophyses of animals kept at 90°F. after thyroidectomy do not show degeneration of beta cells to the same degree that glands from animals kept at 70°F. (approximately) do. A reduction in the number of alpha (oxyphilic) cells is found under all conditions. A brief description of the morphology and normal histology of the gland is included.
The behavior of the karyosome and the ‘peripheral chromatin’ during mitosis and interkinesis in Amoeba proteus with particular reference to the morphologic distribution of nucleic acid as indicated by the Feulgen reaction
Authors: Chalkley H. W.
Published: February 2005

A comparison of preparations stained with Weigert's haematoxylin and with Feulgen's stain shows that contrary to the commonly accepted view the granules of chromatin (sic.) that lie in interkinesis just beneath the nuclear membrane play no part in the formation of the chromatin of the equatorial plate, but break down during the prophase. They contain at best merely traces of nucleic acid. It is possible that these peripheral granules give rise to, or contribute to, the formation of the spindle fibers and the pole caps. The chromatin granules of the plate arise entirely from the karyosome.
Studies on the comparative histology of the digestive tube of certain teleost fishes. III. A bottom‐feeding fish, the sea robin (Prionotus carolinus)
Authors: Blake Irving H.
Published: February 2005

This paper presents the third of a series on comparative microscopic anatomy of the entodermal tract of certain teleost fishes, selected for their feeding habits: A study of the histology of the digestive tube of a bottom‐feeding species, the Carolina sea robin (Prionotus carolinus (L.)). Mainly from study of sections, but dissections of both fresh and preserved material were employed to furnish the necessary background of gross anatomy. A short résumé of the literature is given. Treats the general histology of the different divisions of the tube, the tunics and tissues present, and findings on structure and arrangement of cells. Particular emphasis is placed on histological adaptations to meet the demands of physiological processes. Escphagus, stomach, intestine and pyloric caeca are given detailed treatment. The tunica mucosa, with its histological constituents and their arrangement, receives particular stress, being considered in relation to various phases of digestion and absorption. Particular consideration is given to the following: Effects of amount of food present in the tube on extent of mucosal folding; histological transitions from one region of the tract to another, particularly as regards epithelia; histology of peptic glands in cardiac division of stomach; origin and development of mucosal goblet cells; comparisons between the histology of the pyloric caeca and that of the adjacent intestine from which they arise, together with a detailed account of the histology of the former.
The development and metamorphosis of the mid‐intestinal epithelium of Acanthoscelides obtectus (Say) (Coleoptera)
Authors: Bushnell Ralph Judson
Published: February 2005

Two sizes of cells are found in the mid‐gut epithelium of late embryos. The larger cells contain nuclei having twice the number of prochromosomes and nearly twice the volume as compared with the nuclei of the smaller cells. During each larval instar, the nuclei of the functional mid‐gut epithelium nearly double their volume and there is a corresponding increase in the amount of chromatin. It is suggested that chromosome division without nuclear division occurs in these epithelial cells during the pre‐ecdysial periods of each instar. The mid‐intestinal epithelial cells and their nuclei undergo characteristic changes during the feeding and pre‐ecdysial periods of each instar. Prochromosomes as well as cytoplasmic globules, which represent a cytoplasmic diminution process, are visible in the latter period. The regeneration cells which give rise to the pupal and mid‐gut epithelia have origin from the small embryonic mid‐gut cells and from nuclei and cytoplasm derived from the larval epithelium by means of an apparent ‘pseudoreduction’ of the large larval nuclei during the late third and fourth instars.
The anatomy of the male genital ducts in the fowl
Authors: Gray J. C.
Published: February 2005

The epididymis in the male bird consists of the rete testis, ductuli efferentia, and epididymal tubules. The rete testis is lined with cuboidal epithelium not resting on a basement membrane. When distended with sperm the epithelium appears squamous‐like. The tubuli efferentia are lined for the most part with pseudostratied ciliated columnar epithelium resting on a basement membrane. The epithelium is thrown into permanent longitudinal ridges. The epididymal tubules are lined with ciliated columnar epithelium resting on a bastment membrane.

The three types of genital ducts are intermingled to some extent, but maintain a definite sequence in their connection with one another. The rete testis drains into the tubuli efferentia, and the latter into the epididymal tubules. These drain into the vas deferens.
Oogenesis of Meretrix casta (chemnitz) with a note on the nature of the contents of neutral red vacuoles
Authors: Subramaniam M. K.
Published: February 2005

The Gelgi bodies in Meretrix casta being visible in fresh eggs, an attempt was made to elucidate the nature of the contents of neutral red vacuoles. These are neo‐formations which arise on treatment with neutral red Ringer. As recent researches have shown that neutral red forms compounds with enzymes, it is suggested that the new vacuoles in Meretrix are visible products of the attempt of the Golgi apparatus to eliminate neutral red which is a foreign substance to the egg. The function of Golgi bodies in the control of cell metabolism by production of intra‐cellular enzymes is discussed.
Spermatogenesis of the prawn, Palaemon lamarrei
Authors: Nath Vishwa
Published: February 2005

The spermatozoon of Palaemon lamarrei is like a cricket ball having a small hole at the top. The outer leather covering of the ball represents the nucleus and the internal stuffing the cytoplasmic vesicle, in the formation of which almost the whole of the cytoplasm of the spermatid along with its mitochondrial and Golgi material is sacrificed. The hole is very efficiently plugged with a ring‐like centrosome, which gives off inward a large number of axial filaments radiating through the vesicle toward the nucleus and outward a long prominent spine ending into a fine point. The acrosome is conspicuous by its absence. It has been suggested that, as in Paratelphusa spinigera, the cytoplasmic vesicle forms the mechanism, which is responsible for the explosion of the sperm at the time of fertilization. It has also been suggested that the bizarre structure of the sperm is closely associated with the necessity of ensuring the safety of this explosive vesicle until the time of fertilization. The chromatoid bodies described by Fasten in the crayfish, Cambarus virilis, must be interpreted as the Golgi masses.
A comparative study of the chromosomes of eight genera of Indian Pyrgomorphinae (Acrididae)
Authors: Rao T. Ramachandra
Published: February 2005

In the spermatogonia of all the genera studied, there are nineteen rod‐shaped telomitic chromosomes, which differ considerably regarding their actual sizes in the different genera. However, an analysis of the measurements of second spermatocyte chromosomes shows that as regards proportional sizes and in seriation there is some degree of uniformity within the sub‐family. In Aularches, Atractomorpha, Chrotogonus, Colemania and Pyrgomorpha, the members of the smallest pair of autosomes appear as roundish or oval bodies and are comparable in shape, relative size and behavior with the ‘small’ dot‐like chromosomes of the general Acrididae, while in Orthacris and Zarytes they are not so and merge into the general series. The sex chromosome is the largest one in the complexes, or the second largest as in Poecilocerus. The usual forms of tetrads occur in the spermatocytes. It is found that the number of ring tetrads in any genus depends upon the length of its chromosomes; in genera with longer chromosomes there are more of them than in genera with shorter ones. While no final explanation has been offered regarding the chromosome relationship between this sub‐family and the other Acrididae, some points arising out of the present study have been briefly discussed, and it is shown that a simple process of elimination of two pairs is not sufficient to explain the smaller chromosome number in Pyrgomorphinae.