bluuebunny/crossref_metadata_2025 huggingface dataset:
Musculature of the lacewing (chrysopa plorabunda) neuroptera
Authors: Miller F. W.
Published: February 2005

This article is an account of the complete musculature of an adult Neuropteran insect, Chrysopa plorabunda. Previous anatomical discussions on this order of insects include only a few of the muscles of the head and thoracic regions, while those of the abdomen are entirely lacking. The muscles here described include those of the head, thorax, and abdomen. The origin, insertion, and function of each muscle is given. The boundaries of several of the sclerites, especially those of the labium, are located by the observations on the musculature of these parts. The meso‐ and metathoracic wings are of the same size and for that reason the muscles of these regions are very much alike. The prothorax is greatly elonated, causing the muscles of that region to differ to a greater or less degree from the ‘general rule’ in insects. The abdominal muscles may be arranged in the several groups generally found in insects. In several cases, however, both the origin and insertion of the muscle have been shifted to accompany changes which have taken place in the abdominal segmentation. All of the muscles are shown in the four plates containing nineteen figures which accompany the text.
The chromosomes of schizodactylus monstrosus
Authors: McClung C. E. , Asana J. J.
Published: February 2005

In this peculiar Orthopteron the chromosomes are unusual in these respects: the number is low for one of the Saltatoria; there is an x‐y idiochromosome pair; all the tetrads are individually distinguishable; the chromosomes are small, relatively and actually, in the very large first spermatocyte. The structural peculiarities of the animal are reflected in those of its germ cells, but as yet no correlation has been established.
An experimental study of hemopoiesis in necturus: Effects of lead poisoning on normal and splenectomized animals
Authors: Dawson Alden B.
Published: February 2005

Lead poisoning causes a selective destruction of mature erythrocytes, thereby depleting the spleen and stimulating differentiation and proliferation of erythrocytes in the blood. In conjunction with splenectomy, this intravascular erythropoiesis is markedly accelerated.

During the progressive anemia and subsequent regeneration of erythrocytes in simple lead poisoning the major hemopoietic loci, spleen, mesonephros, liver, and epicardium were observed. The spleen is most rapidly affected. The red cell progenitor first present in the circulation is the hemoblast, but later numerous lymphocytes enter the blood stream and are transformed into erythrocytes.

Following simple splenectomy the blood shows relatively little change. A mild regenerative activity of both erythrocytes and thrombocytes ensues. In lead poisoning after splenectomy the blood picture resembles that of simple lead poisoning. The anemia is produced more rapidly and the regeneration of erythrocytes is delayed.

This study emphasizes the importance of the blood stream of Necturus as a site of red cell differentiation and proliferation, and shows that the lymphocyte may be a possible progenitor of erythrocytes and thrombocytes. Under normal conditions the hemoblast suffices as a source for red cells, but under abnormal or experimental conditions, where the demand for new cells is excessive and prolonged, the lymphocyte plays a major role.
The activity of the coelomic (germinal) epithelium of the male musk turtle, Sternotherus odoratus (Latreille)
Authors: Risley Paul L.
Published: February 2005

Histological studies of testes of both immature and mature individuals show that the peritoneal epithelium does not give up its proliferative capacities with the completion of testis differentiation. Certain regions of the antimesorchial surface retain their activity and continue to contribute cellular elements during testis growth. Stromal cells, germ cells, and sections of or entire seminiferous tubules originate from the peritoneum in the form of cord‐like ingrowths. In this form, the proliferations of the germinal epithelium of the testes are similar to and homologous with the continuous proliferations of the germinal epithelium of the ovary.

In Sternotherus, both testis and ovary differentiate out of a bisexual primordium in which the deeper parts of the germinal epithelium form an ovarian cortex. Since the germinal epithelium persists as an active part of both ovary and testis, it must be responsive to the same physiological factors of female or male differentiation respectively. It is indifferent sexually and once the direction of sex differentiation is established, the response of the germinal epithelium is in the determined direction. Its activity is then to produce either seminiferous tubules or ovarian follicles, and is directly dependent upon the processes of embryonic sex differentiation and determination.
A study of the chromosomes of Xiphophorus, Platypoecilus and of Xiphophorus‐Platypoecilus hybrids during spermatogenesis
Authors: Ralston E. M.
Published: February 2005

During spermatogonial stages in Xiphophorus and Platypoecilus maculatus and Platypoecilus couchiana and in the hybrid, two distinct types of cells are observed, a large lightly staining primary spermatogonium and a smaller deeply staining secondary spermatogonium. Chromosomes of primary spermatogonia of Platypoecilus maculatus and Platypoecilus couchiana differ somewhat from those of Xiphophorus helleri and Xiphophorus jalapa, but are very similar to those of the hybrid at this stage.

Chromosomes of Xiphophorus at this stage are long and thin, while those of Platypoecilus and of the hybrid are somewhat short and thick. Visible chromosome differences appear only during the primary spermatogonial stages.

The haploid group of chromosomes, numbering twenty‐four in the hybrid, so resembles that of Xiphophorus and of these two species of Platypoecilus in both number and morphological characteristics during the primary spermatocyte division as to be practically indistinguishable from either. Persistent lagging of one large chromosome as it comes upon the equatorial plate during the primary spermatocyte division is very noticeable. Precocious division of this chromosome and the advancing of its two daughter components to the poles of the spindle in advance of other chromosomes indicates that this chromosome may be a sex chromosome. The fact that two daughter components are identical morphologically and that each secondary spermatocyte receives one of them suggests that the male in Xiphophorus and in Platypoecilus is homogametic.
Early development in some sciuridae
Authors: Schooley J. P.
Published: February 2005

The early developmental history of Sciuridae (squirrel family), from the ovarian egg to the establishment of the germ layers, was studied in fixed material comprising ova and embryos from six species of five genera. No significant differences were noted in the major processes of development in the six species. Continuous diminution in the size of the ova occurs from the beginning of follicular vesiculation up to the early blastocyst stages. Corpora haemorrhagica are present in most of the recently ruptured follicles of all the species.

Cleavage is regular, though adequal, up to the eight‐cell stage, the blastomeres clustering into a compact mass. There is desquamation of cellular material from the periphery of the ovum between morula and blastocyst stages. At the same time cells within the blastocyst degenerate to add to the cavity originally formed by confluence of intercellular spaces. The cavity forms among the inner cells, an inner cell mass being left at one pole and an anti‐embryonic mass at the other. The anti‐embryonic cells produce much of the yolk‐sac entoderm and contribute to the implantation mass. The latter mass forms a temporary attachment of the blastocyst to the uterine mucosa in these species. The definitive entoderm arises by migration and delamination of certain of the inner cell mass cells. A transitory notochordal canal, passing in a vertical plane through Hensen's node, is strongly suggested.
Spermic dimorphism in Goniobasis laqueata (Say)
Authors: Woodard T. M.
Published: February 2005

Two kinds of spermatozoa are formed in the testis of Goniobasis laqueata, typical (eupyrene) and atypical (apyrene); a similar dimorphism is noted in several other related genera. The development of each type of spermatozoon is described in Goniobasis. The apyrene spermatozoa do not appear in the testis until eupyrene spermatogenesis has progressed to the formation of mature eupyrene spermatozoa. After this time apyrene spermatogenesis becomes predominant. It is suggested that this condition is indicative of a modified protandric hermaphroditism, according to a recent theory of spermic dimorphism. The anatomy of the reproductive system of Goniobasis is described briefly, and the behavior and fate of the two types of spermatozoa are noted. Only the eupyrene spermatozoa are inclosed in a spermatophore formed in a special organ of the male, the apyrenes being somehow excluded. Thus the latter do not reach the female in copulation and can have no necessary functional relationship to the ova at the time of fertilization. The delayed formation of the apyrene spermatozoa, and other facts, indicate that they are probably not concerned with the nutrition or transport of the eupyrene spermatozoa.
The egg capsules of certain Neritidae
Authors: Andrews E. A.
Published: February 2005

The little capsules in which snails of this family deposit eggs are so durable as sometimes to be found adherent to museum specimens; hitherto, however, detailed descriptions of such capsules have been restricted to the capsules long known as made by Neritina fluviatilis in fresh waters of Europe. The present paper adds descriptions, with measurements and sketches, of Neritina reclivata from Florida, Neritina virginea, Neritina punctulata, Theodoxus mneleagris, Nerita peloronta, Nerita alticola, Nerita tesselata and Neritilia succinea from Jamaica, British West Indies.

These capsules are found to be remarkable in that the digestive tract aids in their formation; that is, the capsules are made as secretions of the lower oviduct to which mineral particles are added, and these mineral particles are supplied from the intestine and stored up in a special sac opening into the oviduct. Moreover, the mineral particles are of twofold origin; in some Neritinas they come from the ooze taken in with the food and passed through the intestine; in some Neritas they come from the liver as calcospherites, to be passed through the intestine.

It is hoped that the data given will aid future descriptions of capsules from other species till a firm foundation is built for utilization of these capsules as aids in taxonomy.
The primitive carpus
Authors: Howell A. Brazier
Published: February 2005

There is as yet no proof that the prepollex and postminimus ever occurred as actual digits. Romer's discovery of previous confusion of the preaxial with the postaxial fin border of Sauripterus allows a more accurate interpretation of primitive conditions. The latter involved essential asymmetry. The carpal cartilages of the Sauripterus type offin must have split into transverse rows. When the radius and ulna had become of equal length there was redistribution of the most proximal carpals, thus displacing elements in the other rows. It seems that eventually the original first carpale assumed the position and function of a first metacarpal, while the original fifth metacarpale assumed the position and function of a fifth carpale.
Secondary sexual dimorphism in some Chinese cobitid fishes
Authors: Vladykov Vadim Dmitrij
Published: February 2005

The sexual dimorphism of Chinese cobitids consists of peculiar structures of the pectoral fins and of variations in the lengths of these as well as of the ventral fins. In all groups the paired fins are, as a rule, longer in the male sex, and the female has no lamina circularis, enlargement of pectoral rays or dilation of lateral muscles.

In males of Cobitis and Misgurnus, the second rays of the pectorals are enlarged and possess at their base a bony plate (lamina circularis). In other Chinese genera the lamina circularis is absent. Males of the Misgurnus group are easily recognized by the dilation of the lateral muscles in the region of the dorsal fin. Males of Barbatula have several enlarged inner rays in the pectoral fin and numerous nuptial tubercles on the head, arranged in prepercular and preorbital groups. In the European, B. barbatula, however, tubercles on the head are wanting.

In males of the Leptobotia and probably Botia groups, the first pectoral ray is enlarged, and the membrane between several of the inner rays is covered with nuptial tubercles.

In general, in the Chinese cobitids the differences in sexual dimorphism are correlated with the differences between genera, i.e., each genus possesses a quite different sexual dimorphism; thus the secondary sexual characters can be used for taxonomic purposes.
Cell division and differentiation in asexual and sexual development
Authors: Berrill N. J.
Published: February 2005

In ascidians the development of eggs and of buds are in sharp contrast. In bud development cell sizes are minimal throughout. Gross differentiation of form becomes apparent from the beginning, histological differentiation only when cell division is ending. The position of a cell relative to the whole determines its nature. Multiplication of cells continues until sufficient have been formed for the expression of all specific and other characters. In sexual development the egg is a large cell which divides until the minimal cell sizes characteristic of the species are obtained. The course of cleavage is a curve suggesting the attainment of a state of equlibrium. Commencing before fertilization and continuing during cleavage is a precocious differentiation of certain parts that inhibits further cell division and results in the formation of special larval structures that function when a mere fraction of the whole developmental period has elapsed. This differentiation may be suppressed, or may be retarded, without affecting the development of the rest of the egg. In the remaining parts cell division continues until minimal cell sizes are reached and only then does histological differentiation become apparent, as in asexual development. The number of cells thus formed is very small compared with that necessary for the expression of the full character of the species, and the newly functional postlarval organism is necessarily peculiar in structure.
The early development of the thyroid gland in Amia calva
Authors: Hill Benjamin Harvey
Published: February 2005

The thyroid primordium is a solid median outgrowth from the pharynx which is attached to the truncus arteriosus at its bifuracation. The thyroid is soon detached from the pharynx and migrates to its definitive position ventral to the aorta between the bases of the third visceral pouches. After detachment the primary follicle appears in the lower part of the primordium; during migration and early growth it is divided apparently by stress and pressure to form secondary follicles. Independent follicles are formed also by secretion of colloid between solid masses of thyroid cells. Other secondary follicles are formed by pinching off evaginations from large follicles. Colloid appears soon after the primary follicle is divided. The adult thyroid is a group of follicles scatterd in a venous plexus in the ventral pharyngeal region, around the aorta.
The anatomy and histology of the malpighian tubules and the adjacent alimentary canal in melanoplus differentialis
Authors: Stuart Richard R.
Published: February 2005

The tubules vary in number from about 190 to 300. They gather into twelve groups each consisting of an anterior and a posterior division and each emptying into one of twelve ampullae arranged equi‐distant from each other about the wall of the posterior mid‐gut and in a transverse plane just anterior to the sphincter muscle which marks, externally, the junction of mid‐ and hind‐gut, that is to say, the ‘pyloric valve.’ The lumen of each ampulla is continuous with one of twelve furrows formed by the gathering of the hindgut epithelium into as many folds.

The wall of the digestive tube is made up of, (1) an inner epithelium (tall columnar cells), (2) an intermediate connective tissue layer, and (3) an outer muscular coat (inner circular and outer longitudinal layer). The mid‐gut epithelium dips down at frequent intervals to form crypts at the bases of which are the ‘regeneration centers.’ This epithelium is covered, on its luminar surface, by a curious striated border. The epithelium of the hind‐gut appears to be covered by chitin.

A malpighian tubule consists of a single layer of large polygonal cells with indistinct borders. It is covered externally by a thin membrene made up of ‘peritoneal cells’ and internally by a striated border similar to that in the mid‐gut. Spiralling about each tubule from origin (free end) to insertion (in the gut) is a slender tracheole.
The eye of the monotreme, Echidna hystrix
Authors: Gresser Edward Bellamy , Noback Charles V.
Published: February 2005

The histological structure of the eye of the monotreme, Echidna hystrix is described with reference to its comparative relationships. The eye is primarily mammalian in character but its choroid contains a definite cartilaginous plate and its retina is anangiotic.
The development of the mid‐intestine in melanoplus differentialis (acrididae : Orthoptera)
Authors: Stuart Richard Roy
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 laver os 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 definitivo mid‐gut. Near the of hateching, vitellophanges 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 vitellophage nuclei divede to form the smaller nuclei of the definitive epithelium of the mid‐gut. The development of the definitive mesenteron fron the primitive mid‐gut takes place rapidly and occurs near the time of hatching.
Development of the thyroid gland in the chick embryo
Authors: Hopkins Marie Lockett
Published: February 2005

1. The developing chick thyroid consists of epithelial plates or cords suspended in a sinus, probably lymphoid. These cords in cross section have the appearance of follicles.

2. Growth in size is accomplished by fusion of follicles. Growth in number of the latter by proliferation of inter‐follicular epithelial cells.

3. Colloid first appears on the tenth day of incubation. The tadpole test indicates the beginning of functional activity at this time.

4. During development there is a progressive decrease in the cytoplasm‐nucleus ratio from 3.3: 1 on the third to 1.5: 1 on the nineteenth day, as measured in area, not volume.

5. Not only is chromophobe and chromophile colloid present in different cells of the same follicle at the same time, but both are occasionally present in the same cell at the same time.

6. Evidence of heightened activity in the chick thyroid are as Uhlenhuth (′28) describes them in salamanders: namely, high columnar cells, apically located secretion granules, and vacuoles of chromophobe colloid.

7. Follicles in late developmental stages have, at some time during their functional cycles, tubular exits, which are thought to represent one path through which colloid reaches the circulatory spaces.

8. Vital staining indicates that elements of the reticulo‐endothelial system are present in the developing thyroid. Phagocytic cells in the gland of one embryo were observed phagocytosing entire erythrocytes.
Studies on cell number and the progression factor in the growth of Japanese beetle larvae (Popillia japonica Newman)
Authors: Abercrombie W. Fulton
Published: February 2005

Increases in weight, total body length, and width and length of the head capsule of Japanese beetle larvae were studied. Since the progression factors decreased with succeeding molts and exhibited considerable variation it was concluded that Przibram's principle is inapplicable. Cells were counted in the mid‐intestine and brain. Columnar cells of the mid‐intestine were measured. The data show: (a) No increase in cell number occurs at the time of molting. (b) The progression in weight and length cannot be correlated with an increase in cell number. In the first instar the progression for increase in weight was 5.73; while for increase in cell number, it was 1.67 for the mid‐intestine, and 1.19 for the brain. In the second instar, the corresponding figures were 5.24, 1.98 and 1.69. In the third instar average weight increased 3.18 times, but there was practically no increase in cell number. Thus, molting does not represent a definite increase in number of cells of the insect's body as suggested by Przibram and Megusar, and Bodenheimer's method of calculating cell divisions seems to have no factual basis. Increase in size of the larva is largely due to an increase in cell size. The ratio of increase in total cell volume of the columnar cells of the mid‐intestine is approximately equal to the ratio of weight increase.
Branchial glands in fishes
Authors: Bevelander Gerrit
Published: February 2005

In a comparative study of the branchial epithelium of fishes we find the occurrence of three distinct types and seven subtypes of intra‐epithelial glands which are in intimate association with the branchial epithelium of fishes.

These glands have been classified according to their morphological patterns, cytoplasmic content and other features dealing with structural complexity.

Although these structures arrange themselves in a graded series which become increasingly more and more complex, there does not appear to be any definite correlation between the structural complexity of the glands, and the apparent evolutionary history of the fishes.

We conclude from the characteristic arrangement, relationships, and specific staining reactions that these structures are intra‐epithelial mucous glands.
Oögenesis, fertilization and early cleavage in Habrobracon
Authors: Speicher B. R.
Published: February 2005

Since differential maturation has been used in explaining sex determination in Hymenoptera, the pertinent stages were studied cytologically in Habrobracon by using whole mounts of timed eggs stained by the Feulgen reaction.

The egg is laid with the maturation figure in an arrested first anaphase close to the ventral egg surface, and with the spindle horizontal to the latter. Eggs from different stocks show differences in position of maturation figure. A single sperm enters during oviposition, the maturation spindle revolves to a vertical position and normal maturation and change of the sperm ensues. Nuclei of unfertilized eggs behave similarly. Ten chromosomes enter each of the three polar and the one matured egg nuclei, the latter being always the innermost of the four. Unfertilized eggs have ten chromosomes at first and eleventh cleavages; fertilized eggs have around the expected twenty. Chromosomes in maturation divisions are too small and round to show individual differences. There is no good evidence of chromosome elimination.
The anatomy and histology of the alimentary tract of the grasshopper, melanoplus differentialis Thomas
Authors: Hodge Charles
Published: February 2005

This investigation is intended to be the first of a contemplated series to study correlation of diet with morphological change. The material here reported is from grasshoppers on satisfactory diets. The gross anatomy shows a typically acridine arrangement. Fixation with B3 and staining with haematoxylin and eosin shows that peritoneum, muscle and chitin in different areas vary only in arrangement and relative development. The epithelial cells of the various regions differ in structure as well. Modifications of the cytoplasmic elements of these cells are correlated with cellular activity. The epithelial cells of the mid‐gut and its six bi‐lobed gastric caeca, and of the six rectal glands have a striated border of separate filaments which are cilia‐like in appearance but devoid of motion. The caeca are most active in gastric secretion, which is merocrine or holocrine according to conditions. Essentially different granules and vacuoles are secreted, and extruded by rupture of the cells; which are replaced from nidi.
Haploidy and aberrant spermatogenesis in a coleopteran, Micromalthus debilis LeConte
Authors: Scott Allan Charles
Published: February 2005

The coleopteran Micromalthus debilis LeConte has two additional female reproductive forms besides the male and female adults. One of these is a paedogenetic viviparous female which produces female offspring by diploid parthenogenesis; the other is a paedogenetic ovoviviparous female which produces males by haploid parthenogenesis; The male has been shown to be somatically haploid in both early and late stages of development, while all three female types are diploid. The first spermatocyte division is completely abortive as regards division of chromosomes and cell. However, a very characteristic unipolar spindle is regularly formed. The chromosomes of the first spermatocyte anaphase move away from the single pole with their attachment regions hindermost. The spindle consists of ten fibers, each one connecting a chromosome with a single pole. They elongate during the anaphase. The second spermatocyte division is apparently normal in all respects and it ultimately results in two normal sperm. It has been shown that the theories of Belar, Bleier and Schaede concerning the problem of chromosome movement are deficient in view of the peculiarities of this monocentric mitosis.
Embryology of the nervous system in the grasshopper, Melanoplus differentialis (Acrididae; Orthoptera)
Authors: Baden Victor
Published: February 2005

The development of the nervous system is traced by stages and, in general, is found similar to that already described for other insects. Terms such as ganglionic gangliomeres, medullary masses, optic nerve, etc., are shown to have no significance. The intraganglionic thickening of Viallanes is shown to be a misnomer. A chronological table of the developmental processes is appended.
Spermatophores of the snail Neritina reclivata
Authors: Andrews E. A.
Published: February 2005

Differing from hitherto known spermatophores, these are found to have the form of a loop with a thick body and the slender ends twisted together.

Also one end bears a spiral row of triradiate spicules, unique in being chitinoid secretions. Each is formed within a vacuole of a cell of a small gland found in the males. The ends of the spermatophores hold sperms, but the main mass consists of granules of problematical value. Spermatophores after discharge are stored up within the female, where remnants of them remain indefinitely.

For the first time stages in the formation of spermatophores were found within the males. The head organ in the male is found to be more complex than hitherto known in this genus. A special head organ in the female is described for the first time in this family. An hypothesis is advanced as to the possible use of these male and female head organs in transfer of spermatophores. The suggestion is made that in this family the spermatophores and their organs of transfer and of storage may serve as generic characters.
Cell division and differentiation in the growth of specialized vertebrate tissues
Authors: Cohen Arthur , Berrill N. J.
Published: February 2005

The post‐embryonic growth of the notochord, sensory retinal cells, cartilage and gut epithelium in frog tadpoles, trout and lamprey is described. Increase in the number of notochord and sensory retinal cells results only from the mitotic division of cells which have not yet undergone the structural modifications characteristic for these cells. The specialized and functional cell does not divide. In the frog tadpole the cartilage cells increase by mitotic division of the fully‐formed and functional cell: in addition there are centers of proliferation consisting of small, rapidly‐dividing cells. The trout is similar except that there are no centers of proliferation, in addition amitotic division occurs. The gut epithelium grows by mitotic division of the functional constituent cells. During division the cell assumes a spherical shape and its functional activities are suspended.
Studies in teleostean reproduction. I. Embryonic hermaphroditism in Lebistes reticulatus
Authors: Dildine Glenn C.
Published: February 2005

A study has been made of 155 Lebistes embryos, extending from fertilization until birth of the young. A period of embryonic hermaphroditism begins soon after the formation of the genital ridges (3.0 mm.) and continues until birth (6.5 to 7.0 mm.). Development is first ovarian; evidence is the universal occurrence, in all gonads, of many germ cells in typical ovarian synapsis. The gonads of one‐half of the embryos soon become testicular while those of the other half continue to develop as ovaries. In testicular gonads, all synaptic germ cells undergo pycnotic dissolution as the gonad hilus organizes into a prospective medulla. In ovaries, germ cells in synapsis continue to enlarge as definitive ovocytes. This embryonic hermaphroditism supports Witschi's explanation of sex determination in Lebistes, based on his own work on frogs and on Winge's discovery of unusual XX males in Lebistes. The embryology of gonads in Lebistes also suggests that in teleosts, as in amphibians, birds, and mammals, gonads develop from two distinct portions, a male medulla and a female cortex.
Observations on sperm formation in the centrurid scorpions with especial reference to the Golgi material
Authors: Wilson Edmund B. , Pollister Arthur W.
Published: February 2005

The Mexican scorpion Centruroides shows exactly the same type of chondriokinesis (by ring formation) as that hitherto known only in the related form Centrurus, as earlier reported by one of us ('31). The Golgi bodies show no trace of ring formation but are distributed by random assortment like that of the chondriosomes in other scorpions. The Golgi bodies, clearly visible in vivo, show the typical plate‐like or lamellar structure characteristic of them in other forms. In the first division, after Weigl, there appear to be two metaphase stages, an earlier one in which the dictyosomes are irregularly scattered and a later one in which they tend to mass near the mitotic poles. In the same division, after Champy‐Kull, the (presumable) dictyosomes are regularly massed near the poles and may be traced through the whole mitosis. The neural red bodies (‘vacuome’) undergo an irregular distribution and are cast out in the slough. The problem of distribution and localization in the sperm‐cell formation are discussed with reference to the principle of genetic continuity in the germ cell.
The development of the cortical adrenal in the four‐toed salamander Hemidactylium scutatum (Schlegel)
Authors: Branin Manlif Lelyn
Published: February 2005

Accounts of cortical adrenal development in urodeles are few in number and mostly incomplete from the point of view of development. Hence, an investigation was initiated to fill in existing gaps and present a complete developmental history of the glands in one of the urodeles.

The primary anlagen of the cortical adrenal (interrenal) were seen first in the 8.8‐mm. embryo as paired or unpaired cell groups in the interrenal area of the 'tween zone lying either in contact with or just beneath the coelomic epithelium. It was not possible to determine definitely whether they originate from the coelomic mesothelium or from the subjacent mesenchyme. Subsequent primordia are formed continuously throughout the period of larval development in an antero‐posterior time sequence. Almost immediately they become associated with the postcaval system and the relationship thus established persists throughout life. There is no evidence of a budding process as described by Albrand ('08).

During development there is a progressive increase in the size and number of cortical masses, an increase in the total area occupied by them, and a posterior shifting of the tissue as a whole as determined by its position in relation to the spinal ganglia. The definitive distribution is attained at the time of metamorphosis. The tissue occurs abundantly along the postcava, but strands along the median edge of the mesonephroi, as in some urodeles, are only sparingly developed.
Reproductive system of the bruchid beetles bruchus quadrimaculatus Fabr., bruchus (callosobruchus) chinensis L., (bruchidae—Coleoptera)
Authors: Mukerji Durgadas , Bhuya M. A. Hakim
Published: February 2005

The reproductive organs of Bruchus quadrimaculatus Fabr., and B. (Callosobruchus) chinensis L., including histology are described in detail. The role of the different parts of the male and female copulatory apparatus is discussed and the physical composition and function of the secretions of the accessory glands are indicated. The specific differences in the structure of the genitalia of the two species are shown.
An analysis of the early development of the chick by means of the mitotic index
Authors: Derrick G. Ethel
Published: February 2005

Using the percentage of mitotic figures in the cells as an index, a study was made of the distribution of cell multiplication in the development of the chick embryo. Counts were made of all regions in embryos ranging from the embryonic shield stage to sixteen somites, and of the neural and sensory epithelia and axial mesoderm of older embryos. Figures are presented which are believed to establish the sufficiency of mitotic division in producing the cell increases in the early embryo. In the developing primitive streak, areas of superior division rate were found in the presumptive medullary plate ectoderm at the sides of the streak. The node and the primitive plate tend to exhibit lower rates than the axis of the streak. The posterior nerve cells multiply more rapidly than the average of the neural tube, and areas of activity in the mesoderm tend to be located near the posterior end. An antero‐posterior gradient of the index is indicated in the anterior neural tube, meeting a transient postero‐anterior gradient of the hinder cord in the yolk‐sac region. A lower rate of division in the floor than in the sides of the neural ectoderm may be implicated in the inrolling of the medullary plate and in the ventral ourvature of older embryos. All indices drop progressively with advancing age and differentiation.
The growth, maturation and atresia of ovarian eggs in the rabbit
Authors: Pincus G. , Enzmann E. V.
Published: February 2005

A study is made of the development of ovarian ova in mature rabbit does before and during various stages of pregnancy and after the injection of thyroid and anterior‐pituitary‐like hormones. No appreciable ovogenesis during sexual maturity was found. Nine types of ovarian follicle are distinguished according to size and degree of development. Full ovum size is reached in pre‐antral follicles, and is marked by the formation of a dictyate nucleus and slight reduction in nuclear size. Full follicle size is attained much later. The nature of follicle migration in the course of development is described. Ovum migration within the follicle is found to be a consequence of the nature of the egg's attachments to the follicular epithelium. The least atresia is found in young oocytes (10%), the larger follicles showing about 60% atretic at all stages of the reproductive cycle. The hormone preparations administered affect only the largest follicles and their contained ova.
Changes in the volume, form and internal architecture of the nuclei of the granular glands of the integument of the newt, Triturus viridescens
Authors: Dawson Alden B.
Published: February 2005

Concomitant with the appearance of the early secretion granules the nucleus enlarges slightly, the basichromatin is reduced and discrete acidophilic granules appear within the nuclei. Some nuclei become vacuolated and in others the basichromatin is practically reduced to a thin shell reinforced with occasional chromatic strands. Such nuclei are filled with acidophilic granules.

In many instances the portion of the nucleus adjacent to the secretion is greatly modified, the basichromatin is reduced and presents an alveolar pattern with the alveoli filled with acidophilic material and elongated at right angles to the nuclear membrane. This appearance suggests that material is passing from the nucleus into the cytoplasm but no cytological evidence of such a passage was obtained.

During the storage phase giant nuclei are present. They appear to be the result of a simple hypertrophy but in a few instances it appeared that multiplication by direct division, followed by coalescence might be a contributory factor to their formation.

Following thyroidectomy or hypophysectomy the production of secretion was retarded but no profound regression was observed. After treatment with implants or injections of anterior pituitary a mild stimulation was observed.

The evidence for nuclear participation in the formation of secretion is not conclusive but many of the changes which occur strongly suggest such an activity.
The trophotaeniae of the goodeidae, a family of viviparous cyprinodont fishes
Authors: Turner C. L.
Published: February 2005

The embryos of twenty‐one species of the family Goodeidae have extensive rectal processes (trophotaeniae) which serve as absorptive organs, by means of which the embryos while they are retained in the ovarian cavity absorb substances dissolved in the ovarian fluid. Embryos of three species have not been available for study. No trophotaeniae are present in one species Ataeniobius toweri. There are three general types of trophotaeniae, rosette, sheathed and unsheathed. The structure of the trophotaeniae is sufficiently constant in each species to be used in species determination.
The occipital, otic, basicranial and pterygoid regions of the Gorgonopsia
Authors: Olson Everett Claire
Published: February 2005

This paper is based on information derived from a sectioned skull of Cynariops robustus Broom, a prepared skull of Cynariops longiceps Olson, prepared and sectioned specimens of Captorhinus, Dimetrodon and various cynodonts, and the literature dealing with these forms.

In the otic region, it is shown that the internal auditory meatus, the fallopian aqueduct and the semicircular canals change but little in the series from Captorhinus to the cynodonts. Certain structures, the fenestra ovalis, which becomes progressively smaller, the vestibule, which lies progressively more ventral to the floor of the brain case, the recessus lagenacochlea, which increases in size, and the prootic, which enlarges, show progressive change. The fenestra rotundum is discussed at length. It is absent in Captorhinus, just back of the fenestra ovalis in the Gorgonopsia and Dimetrodon, and confluent with the foramen jugularis in the Cynodontia.

The length and relationships of the parasphenoid in the Gorgonopsia are offered as evidence supporting the theory of the homology of the reptilian parasphenoid and the mammalian vomer.

The sphenethmoid complex in Cynariops is divided into two elements, a basal member, the presphenoid, and a dorsal member, identified as the orbitosphenoid but possibly incorporating a portion of ossified mesethmoid as well.

The comparative studies point out certain basic trends of evolution in the Synapsida, and indicate the level of evolutionary development of the groups studied.
The morphology of the aortic arches in four genera of plethodontid salamanders
Authors: McMullen Eleanor C.
Published: February 2005

The larval, metamorphosing and definitive aortic arches of Desmognathus fuscus, Plethodon cinereus, Eurycea bislineata, and Gyrinophilus porphyriticus, described in this paper, were investigated because it was thought possible that, if the fourth or pulmonary arch failed to develop in these lungless forms, a new factor associated with the loss of lungs might be revealed.

The salient points of structure disclosed, so far as the problem involved is concerned, are: D. fuscus and P. cinereus develop fourth arches which remain functional in the larvae and adults and supply the pharynx, oesophagus, stomach and skin of the shoulder region. In some instances the fourth arch in the larvae of P. cinereus is reduced in length or entirely lacking in which cases correspondingly less of the fourth arch and more of the third arch is present in the adult. E. bislineata and undoubtedly G. porphyriticus fail to develop fourth arches and hence do not possess these in either the larval or adult states.

It is concluded, therefore, that the failure of the fourth arch to develop has evidently not been a factor involved in the advent of lunglessness in plethodontid salamanders. Also, the fact that E. bislineata never develops a fourth arch, yet is able to transform, furnishes additional evidence against Figge's view that Necturus fails to metamorphose because the ventral portion of the fourth arch is absent.
Origin and fate of the median cord in the grasshopper, Melanoplus differentialis (Acrididae: Orthoptera)
Authors: Baden Victor
Published: February 2005

The median cord arises as a hypodermal invagination along the midline from stomodeum to end of tenth abdominal ganglion. It separates from the hypoderm, but does not differentiate into any tissue; apparently it degenerates.
The morphology of the skull of a young Galesaurus planiceps and related forms
Authors: Rigney Harold W.
Published: February 2005

This paper is based on evidence obtained from sectioned skull of Galesaurus planiceps, Owen. Width‐length index of skull is 67.7; height‐width index 47.6. Dental formula is: \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm I\; 3\; or\; 4}}}{{{\rm I\; ?}}} $\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm C\; 1}}}{{{\rm C\; 1}}} $\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm PC\; 7}}}{{{\rm PC\; 9}}} $\end{document}. Length of prevomer is 24.0 mm., that of skull 62.0 mm. Maxilla contains cavity which appears to be equivalen of sinus maxillaris of mammals. Ear structure shows large internal auditory meatus. There is no evidence that horizontal and posterior semicircular canals pass through bone. Fenestra ovalis is large. Parasphenoid, basisphenoid, and basioccipital are fused. Parasphenoid consists of short body and a medial anterior process. Sella turcica lacks floor, probably due to erosion. Detached bone may be sphenethmoid. Dentary contains two canals, probably vascular. Comparisons with related forms lead to following conclusions: (1) Specimen is of young animal. (2) Dental succession of postcanines, distichical replacement of postcanines, long prevomer, short parasphenoid, incomplete osseous incasement of semicircular canals, and other characteristics label Galesaurus as primitive cynodont. (3) Reduction of parasphenoid and development of prevomer support Broom's view that Ictidosaurus is not a cynodont. (4) Prevomer as nasal septum; fusion of parasphenoid, basisphenoid, and basioccipital; large lacrimal, splenial, and articular; and other characteristics indicate that Galesaurus is off line leading to mammals. (5) In certain respects cynodonts are more mammal‐like than gorgonopsians.
Determination of capsaicinoid profile of different chilli peppers grown in Turkey
Authors: Poyrazoǧlu Ender Sinan , Yemiş Oktay , Kadakal Çetin , Artık Nevzat
Published: February 2005

In this research the major pungent components of chilli peppers, namely capsaicin, dihydrocapsaicin and nordihydrocapsaicin, were determined by high‐performance liquid chromatography. Chilli pepper varieties Maraş, Süs, Cin and Isot were collected from different regions (Maraş and Urfa) of Turkey. Capsaicin, dihydrocapsaicin and nordihydrocapsaicin contents of Maraş peppers were 0.81–1.42, 0.38–0.70 and 0.01–0.04 mg g−1 respectively. Total capsaicinoid contents of Süs, Cin and Isot peppers were 2.11, 4.70 and 0.55 mg g−1 respectively, while total capsaicinoid contents of their seeds were 0.63, 1.70 and 1.60 mg g−1 respectively. All the peppers in this study belong to the family Solanaceae, genus Capsicum and species annuum or frutescens. Copyright © 2005 Society of Chemical Industry
Effect of microbial transglutaminase on autolysis and gelation of lizardfish surimi
Authors: Yongsawatdigul Jirawat , Piyadhammaviboon Penprapha
Published: February 2005

In the absence of microbial transglutaminase (MTGase), the textural properties of lizardfish surimi (Saurida spp) improved when pre‐incubated at 4 and 25 °C for 24 and 4 h, respectively. MTGase optimally catalyzed incorporation of monodansylcadaverine (MDC) into surimi at 40 °C. Addition of MTGase appeared to reduce autolytic activity at 25 and 40 °C, but had no effect on autolytic activity at 65 °C. Breaking force and deformation of lizardfish surimi significantly improved when 0.1 unit MTGase g−1 surimi (1.8 g kg−1) was added and pre‐incubated at either 25 or 40 °C. Textural properties improved concomitant with cross‐linked polymers of myosin heavy chain and tropomyosin, but not actin. Addition of MTGase also improved the storage modulus (G′). The gel network of surimi mixed with MTGase and pre‐incubated at 40 °C readily formed during the pre‐incubation period, while formation of the gel network began at 48.1 °C in the absence of MTGase. Copyright © 2005 Society of Chemical Industry
Dynamical stability of compressible drops and stars
Authors: Beyer K. , Günther M.
Published: February 2005

Interest is directed to linearized free boundary motion of a compressible liquid subject to surface tension and self‐gravitation respectively. Linearization relative to an a‐priori given solution to the non‐linear equations leads to a non‐local second order evolution problem to be posed in a space‐time cylinder with variable cross section subject to Fréchet boundary conditions along the lateral boundary part. Well‐posedness of the corresponding initial value problem in a natural weak formulation is proved. Copyright © 2005 John Wiley & Sons, Ltd.
Self‐attracting Fermi–Dirac particles in canonical and microcanonical setting
Authors: Stańczy Robert
Published: February 2005

The existence of stationary solutions for the system describing the interaction of gravitationally attracting particles that obey the Fermi–Dirac statistics is studied depending on the relations between mass, the energy and the temperature of the particles. Copyright © 2005 John Wiley & Sons, Ltd.
Penetration of the zona‐free mouse egg by capacitated epididymal sperm: Cinemicrographic observations
Authors: Wolf Don P. , Armstrong Peter B.
Published: February 2005

Conditions were established for routine cinemicrographic examination of sperm incorporation by living zona‐free mouse eggs employing oil immersion objectives and Nomarski optics. Initial sperm attachment to the egg plasma membrane, which was reversible and appeared to require flagellar activity, involved localized areas of the head corresponding approximately to the position of the equatorial segment. Penetrating sperm lay flat on the egg and, during incorporation, appeared to sink into the egg cytoplasm, accompanied by short bursts of flagellar activity and subsequent rotation of the flagellum around its insertion point. Ensuing sperm head decondensation involved dissociation of individual particulate structures and a dramatic localized clearing in the egg cytoplasm. The normalcy of the penetration process and the potential applicability of this approach was attested to by the observations that polar body extrusion, male and female pronuclear formation, and migration through the egg cytoplasm in preparation for syngamy occurred in several sequences followed for extended time periods.