bluuebunny/crossref_metadata_2025 huggingface dataset:
On the structure and function of the ascidian test
Authors: Das S. M.
Published: February 2005

The test consists of a clear matrix in which cells, fibrils, spicules and vascular tubes are embedded. It is supplied with two main blood vessels which ramify in the test substance and end in a large number of vascular ampullae near the outer surface of the test. Three different kinds of spicules are present. The test cells are of five different kinds. Besides these cells, the author has, for the first time in the history of our knowledge of the Tunicata, demonstrated the presence of nerve cells, nerve fibers and receptor cells in the test. The nerve cells are found throughout the test (except the foot) but are more numerous in the test of the siphons. The epithelial cells of the vascular ampullae act as receptor organs being supplied with nerve fibers that connect them with the nerve cells of the test. Receptor cells are also present in the regions of the test devoid of ampullae (except the foot). Stimuli are received by the receptor cells and conducted by nerve fibrils to the nerve cells, which are in turn connected with the nerve ganglion. The test, therefore, not only serves for the protection and attachment of the animal but also acts as a respiratory and receptor organ.
The cytology of the hypophysis cerebri of the bat
Authors: Sawyer Elizabeth L.
Published: February 2005

A cytological study of the hypophyses of more than 100 female bats, collected at fortnightly intervals from October to April, is reported. The bats were decapitated within 24 hours after collection. and then hypophyses fixed in Champy's fluid or Helly's fluid followed by staining by the acid fuchsin‐thionin‐aurantia method of Kull.

The pars distalis, pars intermedia, and pars nervosa lie adjacent to one another in the flattened gland. In some hypophyses the lumen of the original buccal evagination persists as a narrow residual cleft which may be expanded to form ciliated vesicles.

Observations on cell size. nucleoplasmie ratio, degree of chromaticity in the nucleus, staining reactions of the cytoplasm and secretory granules, and the presence of chondriosomes, secretory granules, and vesicles in the cytosome are recorded. Secretory cells and histiocytes are idintified. Sceretoty cells are found in successive stages of growth, differentiation, secretion, and degeneration. Cells which have discharged their secretion apparently do not resynthesize secretory granules. Mitosis is not observed. The available evidence suggests utilization of a large supply of embryonic cells as the source of the fully differentiated cells. The cells of the pars intermedia are interpreted as potential secretory cells which do not differentiate under the inadequate nutrient conditions of that region.
The bodies of Eberth as a source of connective tissue ground substance in Rana catesbiana, Shaw
Authors: Cameron John Andrew
Published: February 2005

The bodies of Eberth in the skins of tadpoles appear in young stages as fine threads and develop into heavy, amorphous masses in close contact with the basal membranes of the epidermal cells. They possess extensions which pass from the epidermal cells through their membranes into the corium. During metamorphosis, when the amount of dermal connective tissue is greatly increased, the bodies disappear the more distal first and the most proximal latest. The processes which pass into the dermis are the last parts to remain visible. Examination of a series of stages suggests that they pass through the cell membranes of the epidermis and into the corium. The bodies then, may be regarded as reserve accumulations of secreted material which are used up in the formation of dermal connective tissue. This explanation accounts for three otherwise unexplained peculiarities of the skin of the developing frog: (1) the presence and growth of the bodies of Eberth; (2) their disappearance during metamorphosis; (3) the sudden large increase in connective tissue fibers of the dermis at metamorphosis.
Observations upon the aglomerular nature of certain teleostean kidneys
Authors: Grafflin Allan L.
Published: February 2005

Observations are reported which fully establish the aglomerular nature of the kidney in the following teleostean species: Hippocampus trimaculatus, Hippocampus kuda, Hippocampus hudsonius, Microphis boaja, Batrachus grunniens and Pterophryne histrio. It is possible that we are dealing with an additional aglomerular species (Microphis sp.), but this cannot be determined from the available material. All species were taken in sea water except Microphis boaja and Microphis sp., which were taken in fresh water.
Sexual dimorphism in north American hawks I. Sex organs
Authors: Stanley Allan J.
Published: February 2005

The development of the gonads of the marsh hawk, Circus hudsonius, Cooper's hawk, Accipiter cooperi, and the red‐tailed hawk, Buteo borealis borealis has been investigated. The occurrence and relatively long persistence of the cortex on both testes of the marsh hawk is evidence of bilateral amphisexuality in this form. The embryonic condition of the ovaries is related to the degree of asymmetry in the adult organs. Nearly symmetrical, paired ovaries were found in three species and varying amounts of reduction of the right ovary in all others.

The disappearance of the right oviduct in the ontogeny of the female red‐tailed hawk and the occurrence of accessory gonad tissue in male embryos of the same species are described and figured. The extent of reduction of the right ovary of eleven species is described, figured and classified. The following species are listed in the above order of classification: Circus hudsonius, Accipiter cooperi, Accipiter velox velox, Accipiter atricapillus atricapillus, Falco sparverius sparverius, Aquila chrysaëtos canadensis, Buteo borealis borealis, Buteo lineatus lineatus, Buteo lagopus sancti‐johannis, Cathartes aura septentrionalis, Buteo platypterus platypterus.

It is concluded that two ways by which organs may disappear are realized in the right ovary and oviduct of the hawks. (1) by failure of an embryonic inductor in the case of the ovary, and (2) in the right oviduct by secondary atrophy of an originally well‐developed embryonic structure.
Oogenesis in a thelytokous wasp, Nemeritis canescens (Grav.)
Authors: Speicher B. R.
Published: February 2005

In the fifty generations of reared Nemeritis, males have been totally lacking. Oogenesis is atypical in (1) the occurrence of a pronounced and lengthy prochromosome stage, (2) the partial fusion of the eleven tetrads at early first anaphase, (3) following first anaphase, a return of all dyads from both poles to form a common second metaphase plate consisting of twenty‐two separate dyads, (4) a second division which forms a single polar nucleus and an egg nucleus, each with twenty‐two chromosomes, (5) the parthenogenetic development of the egg nucleus with twenty‐two chromosomes. Oviposition, which occurs at first anaphase, is followed by a pronounced swelling of the egg through osmosis. Oogonia, follicle cells, cleavage nuclei and somatic cells in later embryogeny all show twenty‐two metaphase chromosomes, while pupai tissue shows also tetraploid and octoploid complexes.
The morphology of the hypophysis of amblystoma
Authors: Roofe Paul Gibbons
Published: February 2005

This paper presents an account of the morphology of the hypophysis and adjacent hypothalamic regions of young adult Amblystoma tigrinum. The description deals primarily with reconstructed models made from blotting paper; transverse and sagittal sections are also considered. A new term, hypophysis, pars subdistalis, is used to describe a discrete portion of the hypophysis embedded in the medial and ventral portion of the pars distalis. The other portions of the hypophysis also are described in detail.
Some factors in the morphogenesis of vertebrate embryonic epithelia
Authors: Sauer F. C.
Published: February 2005

This paper correlates the various aspects of the author's previous work on embryonic columnar epithelia and deals especially with the mechanical factors that determine the form of an epithelium. The origin of the terminal bars, the various forms the terminal bars assume, and the significance of the terminal bar net in maintaining the epithelial structure are discussed. The paper also gives detailed consideration to the elongation of columnar cells after division. When this change in shape cannot be attributed to crowding from without, it is suggested that a thrusting action of elongating spindle fibers is the internal force responsible. In either case elongation is influenced by the development of the terminal web limiting the free surface. Further observations on this structure, first described by the author in 1935, are presented. The terminal web, which is generally present in columnar epithelia, is a specialized part of fixed cytoplasm, condensed, and lying in the plane of the terminal bars. It disappears in mitosis, but its reappearance as the new cell elongates limits the area of the free end of the cell. Hence, the terminal web plays an important part in determining the form of columnar cells.
Comparison of the weights of suprarenals of dogs in oestrus, pregnancy and lactation
Authors: Baker Dan D.
Published: February 2005

Comparisons have been made of the weights of the suprarenals of 525 mature female dogs in dioestrus, oestrus, pregnancy and lactation. Tables and graphs show that there was a slight increase in the size of the suprarenals during oestrus. There was hypertrophy of both the cortex and the medulla in the oestrous dogs. Only slight increase was shown in the weights of the glands of pregnant animals when the net body weight was considered and no increase when the total body weight was used in the study. There was no hypertrophy of the glands of lactating animals.

There was only a slight variation in the seasonal occurrence of oestrus. From 34 to 37% of the total numbers of mature females examined in the seasons were found to be in oestrus. From 13 to 16% of the total numbers were found to be pregnant.
The centriole in the parthenogenetic and fertilized eggs of Habrobracon juglandis
Authors: Spotkov Elias Morlenn
Published: February 2005

Cyto‐centrosomes containing centrioles but lacking asters originate de novo in great number throughout the ooplasm of Habrobracon eggs during the formation of the first maturation metaphase. These cyto‐centrosomes apparently arise from accessory nuclei which are formed from granules extruded by the germinal vesicle. The accessory nuclei react negatively to the Feulgen nucleal test.

Asters similar to those present in artificially parthenogenetic eggs appear around many of the cyto‐centrosomes, thus forming cytasters. These are manifest only after the female pronucleus establishes an association with a cyto‐centrosome, which thus becomes the nuclear centrosome.

In the parthenogenetic egg the centriole of the nuclear centrosome is continuous from one cell generation to the next, whereas the centrioles of the cyto‐centrosomes which are unassociated with nuclear material are not perpetuated and disappear during early cleavage.

Concerning the origin of the first cleavage centrioles in fertilized eggs, evidence shows that in some ova it is entirely maternal, that is, from two cyto‐centrosomes, one associated with the female pronucleus and occupying one pole of the first mitotic spindle, and the other associated with the male pronucleus and located at the opposite pole; while in other ova it is maternal‐paternal; from two centrosomes, one the sperm centrosome which occupies one pole of the first cleavage spindle, and the other a cyto‐centrosome associated with the female pronucleus and situated at the opposite pole.
Histological and cytological changes in the ovary of Cymatogaster aggregatus during gestation
Authors: Turner C. L.
Published: February 2005

Viviparity in the teleost fishes is most highly developed in the family Embiotocidae. In Cymatogaster aggregatus, a member of this family, the males are sexually mature at birth. Females born in June and July are inseminated soon after birth and carry the spermatozoa in the ovarian cavity until December when eggs are fertilized. Embryos are retained in the ovarian cavity till the following spring when they are born.

The cells of the epithelium lining the ovarian cavity develop internal fluid reservoirs which reach their maximal stage in early gestation when there is an extensive sloughing of epithelial cells. The epithelium returns to its original condition in late gestation and later the cells undergo multiplication. The stroma becomes swollen and contains a large amount of fluid during early gestation and shrinks as the embryos become larger. Many of the eggs, failing to reach maturity at the time of fertilization, degenerate. Degeneration also takes place in numerous smaller ovocytes during gestation but some of them survive to grow during the next season.

The cyclical changes in the ovarian tissue of Cymatogaster aggregatus are parallel to those which occur in the ovaries of the Goodeidae and the Jenynsiidae, two other families in which viviparity has been highly developed.
The early development of the avian embryo. I. Endoderm formation
Authors: Jacobson W.
Published: February 2005

In the blastula stage the roof of the subgerminal cavity is composed of an irregular layer of cells, the nuclei of which lie in the upper or middle part of the cytoplasm.

On the floor of the subgerminal cavity groups of already degenerating cells occur. They represent the vegetative pole of the blastula. Almost every cell contains glycogen, and mitotic cells show no special orientation.

In the gastrula stage the cells of the area pellucida become regularly arranged as a single‐layered, cylindrical epithelium with basally situated nuclei.

The yolk endoderm cells are formed from the proliferating upper layer of the area opaca.

The embryonic endoderm is formed at the posterior end of the area pellucida by outgrowth of single cells from a circumscribed area, the primitive plate.

This plate eventually bends inward to form a typical archenteric canal, through which endoderm continues to invaginate from the epiblast.

The endoderm spreads in a cranial and lateral direction until it has formed a complete layer.

The epiblast cells lose their glycogen as they invaginate to form endoderm, which is free of glycogen.

In the area opaca the upper layer and the yolk endoderm contain glycogen.

The mitotic cells of the epiblast of the area pellucida are always orientated horizontally, but in the primitive plate and archenteric canal they are orientated vertically as well.
The early development of the avian embryo. II. Mesoderm formation and the distribution of presumptive embryonic material
Authors: Jacobson W.
Published: February 2005

The first mesoderm cells, and therefore the primitive streak, originate from the epiblast in an axial zone of the third quarter of the area pellucida.

The primitive streak grows by epiblastic proliferation only, without any forward movement of the epiblast.

Presumptive mesoderm cells invaginate during the existence of the streak.

The endoderm plays no part in forming the mesoderm and head process.

The epiblast cells lose their glycogen when invaginating through the primitive streak or node, to form the mesoderm or head process, both of which are free of glycogen.

When invaginating, the epiblast cells show an increase of lipoids (probably sterols) which decrease as they become mesoderm cells, but are retained in the head process. The higher lipoid content is correlated (1) with the organizing effect of the primitive streak, node and head process; (2) with the behavior of Nile blue marks, which when reaching the streak, node or head process are retained and no longer follow the movements of the individual cells.

The shortening of the primitive streak is effected by the approximation of the epiblast from either side, which begins at the cranial end of the streak and spreads caudally. There is no backward migration of the cells of the primitive node.

The arrangement of the presumptive embryonic material in the epiblast at the end of the blastula stage is described.
The changes in the central nervous system during the life history of the beetle, Passalus cornutus fabricius
Authors: Cody Frances Perle , Gray I. E.
Published: February 2005

In early embryonic stages of Passalus there are, in addition to the brain and suboesophageal ganglion, three thoracic and ten abdominal ganglia; one ganglion to each body segment. Before hatching the tenth, ninth and eighth abdominal ganglia coalesce. During the three larval instars the terminal ganglion remains in the sixth abdominal segment and only minor changes occur. By the end of the third day of pupal life the adult form of the nervous system is practically assumed. All abdominal ganglia are fused into a single, solid, elongated ganglionic mass. Connectives have disappeared between meso‐ and meta‐thoracic and between metathoracic and abdominal ganglia; and with exception of the brain, sub‐oesophageal and prothoracic ganglia, the entire ventral chain has come to lie in the mesothorax. The peripheral nerves still arise from the ganglia and ganglionic mass in their same relative positions and still supply the same segments in which they were originally located.
The development of the imaginal eye in the larva of Drosophila melanogaster
Authors: Enzmann E. V. , Haskins C. P.
Published: February 2005

A study has been made of the growth of the eye anlage, and of the increase in number of the elements of the dioptric system of larvae of Drosophila melanogaster.

In newly hatched larvae the eye rudiment grows fast, but slows down later and becomes nearly stationary during the second half of larval life. The increase in number of elements in the eye disc parallels the growth of the whole anlage and reaches a maximum about 70 hours after hatching. The imaginal disc cells increase in number but not in size, in contrast to other larval cells which increase in size but not in number.
The comparative morphology of the vertebrate spinal column. Its form as related to function
Authors: Rockwell Helen , Evans F. Gaynor , Pheasant Homer C.
Published: February 2005

The form of the vertebral column is definitely related to its function as a supporting rod, a base for attachment of body and limb muscles, and a protection of the spinal cord and nerves. Primitively composed of a series of simple undifferentiated blocks, it progressively becomes complicated through development of articular processes giving added strength and greater mobility. Simultaneously, the centrum and the neural arch become adapted to withstand tension and compression stresses which vary with the movements possible in different regions of the column. These movements are partially determined by the plane of the zygapophyses and the nature of the intercentral articulation, together with the action of the axial muscles and ligaments.

In fish and primitive tetrapods the axial musculature serves as the chief locomotor organ and consists of a series of myomeres extending with little interruption from the head to the tail. In tetrapods the locomotor function is taken over by the limbs and the axial muscles become progressively differentiated into long flexors and extensors of the column and gradually lose their external segmentation.
Sexual differentiation of urogenital ducts of Ambystoma tigrinum
Authors: Rodgers Leland T. , Risley Paul L.
Published: February 2005

Adult salamanders of Ambystoma tigrinum show a high degree of sexual dimorphism. The normal growth of the urogenital ducts system in relation to the development of the gonads is traced from the sexually indifferent period preceding metamorphosis to sexual maturity at 1 year. Differentiation and growth of secondary sex characters is correlated with spermatogenesis in the male and with growth of ovocytes in the female.

Testicular hormone manifests its initial appearance in male differentiation of the wolffian and urinary collecting ducts following metamorphosis. Growth of ovocytes and oviducts begins before metamorphosis and may be assumed to indicate the initial appearance of the ovarian hormone. Females retain the larval arrangement of wolffian and urinary ducts. The oviducts of the male regress during the period of rapid male differentiation. This suggests the possibility of antagonistic activity of the male hormones in Ambystoma.
Blood‐cell changes during experimental nutritional deficiency anemia and recovery in the newt, Triturus viridescens, with special reference to the erythrocytes
Authors: Jordan H. E.
Published: February 2005

A batch of fifty newts was subjected to complete food deprivation for a period of 4 months. During the experiment twenty‐two individuals died and twenty‐eight were killed at intervals. From the end of the second month the erythrocytes began to show in increasingly greater numbers a progressive alteration in the nucleo‐cytoplasmic ratio. The nucleus of these atypical erythrocytes gradually enlarged and ultimately occupied the entire cytosome. Meanwhile the nuclear reticulum became extremely fine and closely meshed, eventually appearing practically homogeneous and relatively chromophobic. The end result was complete dissolution. The leukocytes became greatly reduced in number, the eosinophils disappearing completely. The neutrophils and basophils were agranular in the blood smears. The erythrocyte transformations represent late results of a chain of factors: cytoplasmic hypotonicity, nuclear endosmosis, attenuation and fenestration of nuclear membrane. The subcapsular lymphogranulocytopoietic tissue of the liver had almost completely disappeared. The spleen was greatly reduced in size; it was essentially lymphoid in character and erythrocytopoietic activity had ceased practically completely. Complete restoration of normal conditions in blood, liver and spleen was effected by the end of 2 weeks by feeding with earthworms. The regenerating blood showed many naked nuclei of disintegrating atypical erythrocytes, many immature erythrocytes in mitosis, increased number of small lymphocytes (lymphoid hemoblasts), large but variable numbers of microcytes, many giant thrombocytes and normal granulocytes.
The absorption of colloidal carbon from the body cavity of Ammocoetes. A study of the structure and function of the larval kidneys and blood forming tissues
Authors: Torrey Theodore W.
Published: February 2005

Colloidal carbon injected into the coelom of the larval lamprey, Ammocoetes, is taken up directly by the pronephric tubules. Due to the absence of nephrostomes the mesonephric tubules do not function in a similar way. The tubules of neither show any intracellular deposition of carbon. The reticular elements which support both these kidneys exhibit pronounced phagocytic and hemocytopoietic activity. Carbon in either a free or included form reaches all the other organs both as a result of direct invasion or secondary distribution by the vascular system. The liver is the only organ whose vascular endothelium exhibits cytopoietic properties. To the diffuse spleen as a site of blood cell formation thus should be added the reticular tissue of the pronephros and mesonephros and the vascular endothelium of the liver. Playing a minor role in a similar way are the intestinal mucosa exclusive of that in the typhlosole and the spongy tissue dorsal to the neural tube.
A cytological study of the pleuropodia of Melanoplus differentialis (Orthoptera, Acrididae) which furnishes new evidence that they produce the hatching enzyme
Authors: Slifer Eleanor H.
Published: February 2005

In an earlier paper (Slifer, '37) experiments were reported which showed that in Melanoplus differentialis eggs the hatching enzyme, which destroys the white cuticle, is secreted by the pleuropodia (appendages of the first abdominal segment of the embryo) during the last few days of incubation. In the present report the development and differentiation of the pleuropodia, together with the cytological changes which occur in them before, during and after they become functional, have been followed. The time at which the secretion granules are discharged from the pleuropodial cells was found to be closely correlated with the time at which the tough, white cuticle begins to disintegrate. The cytological evidence, then, supports the author's earlier conclusion, based upon experimental work, that the pleuropodia secrete the hatching enzyme.
The follicular cycle in the sexually mature thirteen‐lined ground squirrel (Citellus tridecemlineatus Mitch.)
Authors: Pliske Edward C.
Published: February 2005

The germinal epithelium was studied in an effort to determine its role in postpubertal ovogenesis. Active and inactive areas of epithelium were observed regardless of the oestrous periods. The active areas, exemplified by numerous mitoses and a frequent stratification of the epithelium, are foci for egg cell production.

Egg cells are produced from the germinal epithelium by: activation, migration and transformation of single germinal epithelial cells; migration and differentiation of nests of cells; ingrowths of cords of cells.

Young ova in the cortex of the ovary are at first surrounded by a single layer of flattened follicular cells of germinal epithelial origin. In the subsequent development of the follicle stratified layers make their appearance. The zona pellucida appears as a well‐defined structure coincident with the stratification of the follicular layers.

The follicular cavity develops as a split between the follicular cells at one side of the follicle. In the mature follicle the cavity is broad and contains liquor folliculi. The theca interna and externa are not distinguishable until the follicle is highly cellular.
Studies on the structure of nucleolusforming regions and related structures in the giant salivary gland chromosomes of Diptera
Authors: Poulson D. F. , Metz C. W.
Published: February 2005

Salivary gland nuclei in Chironomus regularly show large, conspicuous nucleoli. In Sciara no true nucleoli have been found, but sometimes certain particular chromosome regions expand greatly, forming ‘puffs’ or ‘bulbs,’ somewhat nucleolus‐like in nature. Detailed study has been made of the chromosome structure in the affected regions in both genera.

In the nucleolar regions of Chironomus the banded structure of the chromosome is distinctly modified. In the case of the large nucleolus the chromosome breaks up into a heavy network in which solid discs are replaced by interconnected chromatic spheres and granules, extending out somewhat into the clear nucleolar substance. In the case of the smaller nucleolus, Balbiani's ring, the banded structure is less disturbed. A chromatic network, resembling a system of rootlets, runs out from the chromatic bands into the clear nucleolar substance.

In Sciara ocellaris the ‘puff’ regions are at times normally banded, but at other times in the condition described as ‘puffed.’ The same is true of the ‘bulb’ regions. The relation between nucleoli, puffs and bulbs is discussed. Also that between ‘heterochromatin’ and ‘euchromatin.’ Evidence seems to indicate that the latter are merely extremes in a continuous range involving different relative amounts of chromatic and achromatic materials. The ‘puff’ regions appear to be structurally similar to the chromocenter in Drosophila.
The postpartum formation of egg cells in the cat
Authors: Kingsbury B. F.
Published: February 2005

The summary of this paper is as follows:

From an examination of 108 ovaries from eighty‐nine individuals it was apparent that, in the cat a certain but variable amount of degeneration of primary follicles occurs in all life epochs.

The primary oocytes undergo the degeneration, while the follicle cells remain for an undetermined time.

The most profound instances of such degeneration were encountered in kittens of 6 to 9 weeks, accompanying or follwing the resolution of the egg cords into primary follicles and the establishment of the cortical or marginal zone. A sporadic degeneration of young oocytes occurs at earlier periods.

No evidence was seen of a new formation of egg cells from the residual follicle cells after the degeneration of the oocytes. The degenerations of the 6 to 9 weeks epoch are not believed to be of universal occurrence.

No adequate evidence was encountered of a new formation of egg cells from the surface epithelium, either before or after sexual maturity.

No evidence linking the degeneration of primary follicles with the estrous cycle was seen.

The stock of primary follicles established in the first few weeks after birth is believed to be adequate for the growth of graafian.
On a new law of the bi‐triangular medial concentration of the cephalic appendages in the chilopoda and the insecta
Authors: Roonwal Mithan Lal
Published: February 2005

A law of the “bi‐triangular medial concentration of the cephalic appendages” in the Chilopoda and the Insecta is propounded. According to it, the cephalic appendages lying in front of and behind the intercalary pair of appendages undergo a concentration, both in phylogeny and in ontogeny, toward the median line. In this way, two hypothetical triangles, termed the ‘anterior or procephalic triangle’ and the ‘posterior or gnathocephalic triangle’ are formed, having a common base in the level of the intercalary appendages. The cephalic appendages occupy roughly either the sides or the apices of the triangles and the degree of their final medial concentration is in direct proportion to their distance from the triangular base. Before the final bi‐triangular condition is achieved by the appendages, varying types of transitory shiftings are passed through.
Mitochondria in liver cells of fed and starved salamanders
Authors: McCurdy Mary Burton Derrickson
Published: February 2005

In the hepatic cells of well‐fed salamanders (Triturus pyrrhogaster) elongated mitochondria predominate which exhibit a diversity of shapes. Starvation tends gradually to produce a shift in predominance from the elongated to the granular forms of mitochondria; terminally looped and ring‐shaped mitochondria also characteristic of the well‐fed condition, gradually become rare to absent. Beaded elongated mitochondria increase in number after short periods of fasting, and appear to be transitional between smooth elongated mitochondria and granular mitochondria.

Re‐feeding tends to bring about a recovery of the mitochondrial picture of the well‐fed animals.

There are exceptions to the above general trend which show that the length of starvation and digestive activity are not the only factors that account for the changes in the mitochondrial condition. A closer relation is found between the mitochondrial condition and the relative amounts of fat and glycogen in the cell. It can be stated as a rule that the shift in predominance from elongated mitochondria to granular mitochondria parallels the decrease in amount of fat and glycogen in the cell.
Glands in the head capsule of coccinellid beetles with a discussion on some aspects of gnathal glands
Authors: Pradhan S.
Published: February 2005

Glands are classified by structure as multicellular complex acinose, multicellular simple tubular, and unicellular; by position as general, hypodermal, ocular, anternnal, intra‐mandibular, mandibular, mandibulo‐maxillary, maxillary, intra‐cardonal and labial. Some open outside the extra‐oral cavity. They are supposed to be offensive in function. The segmental origin of the gnathial is doubtful.
Public–private partnerships in the defence industry and the extended corporate intelligence and national security model
Authors: Trim Peter
Published: February 2005

This article confirms that public–private partnerships in the defence industry share both economic and political dimensions.

Restructuring and consolidation will result in greater strategic integration and firmer links between defence companies and government.

Tasks currently undertaken by independent security companies can also be performed by government intelligence and security agencies.

By drawing on the knowledge of defence industry experts it is possible to provide a more comprehensive understanding of what corporate intelligence is.

Corporate intelligence is establishing itself as a separate body of knowledge.

Copyright © 2001 John Wiley & Sons, Ltd.
Immunization of female rabbits with heat‐solubilized bovine zonae: Production of anti‐zona antibody and inhibition of fertility
Authors: Gwatkin R. B. L. , Williams D. T.
Published: February 2005

Bovine zonae were solubilized by heating to 80°C in buffered saline. On injection of female rabbits with this solution, zona‐specific antisera were produced that could be assayed on bovine eggs in vitro by immunofluorescence, coating, and inhibition of sperm‐binding. When the latter was complete, the rabbits were found to be infertile. Immunofluorescence assays showed that the rabbit anti‐bovine zona serum reacted as strongly with rabbit and rhesus monkey zonae as with homologous zonae. Strong cross‐reaction was also observed with marmoset and dog zonae, but with hamster zonae the reaction was relatively weak.
Respiration rates and sugar utilization by marsupial spermatozoa
Authors: Rodger John C. , Suter D. A. I.
Published: February 2005

This paper reports the first metabolic study of marsupial spermatozoa. The oxidative metabolism of the spermatozoa of the Australian brush‐tailed possum (Trichosurus vulpecula) was examined using a micro Warburg system. Semen was collected by electro‐ejaculation and washed twice in Ca2+ free Krebs‐Ringer‐phosphate buffer containing antibiotics (KRPA). Washed spermatozoa suspended in fresh KRPA, were then incubated for 3 hours at 37° C in the presence and absence of added substrates (4 mM). The exogenous substrates tested were N‐acetylglucosamine, glucosamine, and glucose. Small quantities of radioactively labeled [14C] substrates were included in the incubation media to allow measurement of substrate oxidation.

Although the respiratory rate varied considerably between semen pools (replicate experiments), the relationship between total oxygen consumption (measured manometrically), and oxygen consumption accounted for by exogenous substrate utilization (calcuated from radioactivity recovered in the respiratory CO2) was remarkably consistent. Oxidation of exogenous substrate accounted for 49–54% of the oxygen consumption, depending on the substrate used. There was, however, no evidence that addition of these substrates stimulated the respiratory rate over that found when no substrate was added. Lactate formation accounted for the greater part of exogenous substrate consumed.
Adenosine 3′,5′‐cyclic monophosphate‐binding protein in sea urchin eggs and embryos
Authors: Fujino Yukio , Yasumasu Ikuo
Published: February 2005

Adenosine 3′,5′‐cyclic monophosphate (cAMP) binds to high‐molecular substances which are probably proteins, in homogenates of sea urchin eggs and embryos. The bound cAMP is exchangeable. Optimal pH for the binding capacity of the proteins with cAMP is 4.0, and is shifted to 5.0 in the presence of 5 mM caffeine. The level of bound cAMP increases steeply during 10 minutes of incubation. This is then followed by a less steep increase. The level of bound cAMP decreases in the presence of NaCl. The dissociation onstant between cAMP and the proteins in homogenates of unfertilized and ertilized eggs is about 10 nM, and the value in the embryos at the gastrula stage is lower than that in the unfertilized egg homogenate.
Bovine and hamster zona solutions exhibit receptor activity for capacitated but not for noncapacitated sperm
Authors: Gwatkin R. B. L. , Williams D. T.
Published: February 2005

Hamster and bovine zonae pellucidae were dissolved by heating them in buffered saline for 35 min at 65°C and 80°C, respectively. Pretreatment of noncapacitated sperm with these solutions did not affect their binding to eggs, but the binding of cumulus‐capacitated hamster sperm and of bovine sperm that had undergone a capacitation‐like surface change in response to hypertonic‐treatment was severely curtailed. These experiments demonstrate that such zona solutions exhibit receptor activity, but only for the capacitated sperm.
Development of a culture medium for growing xenopus laevis oocytes
Authors: Wallace Robin A. , Misulovin Ziva , Jared Donald W. , Wiley H. Steven
Published: February 2005

A defined medium for growing defolliculated Xenopus laevis oocytes was developed by monitoring vitellogenin incorporation. Optimum conditions were achieved by use of 50% Liebovitz L‐15 medium supplemented with 1 mM L‐glutamine, 15 mM Hepes, 5 mg/ml vitellogenin, and 1 μg/ml insulin (final pH = 7.8). Stage IV/V oocytes remained morphologically normal in this medium for at least two weeks and grew at an average rate of 0.25 mm3 per week. This is the first time defolliculated Xenopus laevis oocytes have been grown in vitro.
Effect of elevated calcium concentration on fertilization of rat oocytes in vitro
Authors: Kaplan Ruth , Kraicer P. F.
Published: February 2005

The purpose of this study was to develop a modification of the medium of Toyoda and Chang which would permit high rates of fertilization in vitro in rats of our colony. Elevation of the calcium concentration from 1.71 to 3.42 mM increased the fertilization rate by 87%. Greater additions of calcium gave no further improvement. This effect was not due to reduction in phosphate activity, nor was it due to antagonism of heavy‐metal contamination. Although calcium is known to enhance the fertilizing capacity of spermatozoa, our results suggest that it may also affect the oocyte.
Mouse egg penetration is inhibited by Erythrosin B
Authors: Carroll Edward J. , Wolf Don P.
Published: February 2005

The anionic fluorescein dye, Erythrosin B, inhibited the penetration of mouse eggs in vitro. High concentrations of the dye (0.5–1.0 mM) inhibited the penetration of cumulus‐intact, cumulus‐free, and zona‐free eggs at sperm concentrations of approximately 2 × 105 cells per milliliter. Examination of gamete viability indicated that the dye did not cause gross, irreversible changes in either amete, and we therefore concluded that dye‐dependent inhibition may have resulted from dye association with cell membranes. The dye concentration required to give 50% inhibition, apparent I50, of 500 μM obtained for zonafree eggs was artificially elevated by the presence of bovine serum albumin (BSA) (2%) in the culture medium. A corrected I50 of 11 μM was estimated in the absence of BSA.
Inability of exogenous luteinizing hormone to accelerate maturation of oocytes from gonadotrophin‐treated immature rats
Authors: Kaplan Ruth , Kraicer P. F.
Published: February 2005

Immature rats, aged 27 days, were stimulated to develop preovulatory follicles by subcutaneous injection of 15 IU of pregnant mare serum gonadotrophin (PMSG). Two days later their oocytes were collected. They were cultured under conditions that permitted continuous observation. Times of the initial stages of maturation were carefully noted, in the absence and the presence of 10 μg/ml of bovine luteinizing hormone (LH). LH did not accelerate germinal vesicle disappearance. It was concluded that the immature PMSG‐treated rat was not an appropriate model for the study of LH action; it was speculated that persistence of PMSG mimicked LH in all the oocytes from such donors.
Localization of zona antigen in bovine ovary sections by fluorescent antibody
Authors: Gwatkin R. B. L. , Meyenhofer M. , Williams D. T.
Published: February 2005

Treatment of bovine ovary sections with rabbit antibovine zona serum followed by fluorescein‐conjugated goat antirabbit IgG produced a specific fluorescent staining only of the zonae pellucidae. Fluorescence was greater near the inner and outer surface of the zona, suggesting that either the same antigen occurs in higher concentration in these regions or that there is more than one antigen, the most immunogenic being located peripherally. In some atretic follicles fluorescent material appeared to diffuse into the degenerating oocyte and into the intercellular spaces of the cumulus oophorus.
Cytological effects of urethan on cleavage induction in parthenogenetically activated sea urchin eggs
Authors: Nakashima Seiko , Ishikawa Masaru
Published: February 2005

The effect of urethan on artificial induction of cleavage in eggs of the sea urchin, Hemicentrotus pulcherrimus, was studied. When the eggs were exposed for 20 minutes to seawater containing urethan (final concentration, 0.08 M) after butyric acid‐activation and then treated with hypertonic seawater, the cleavage rate was enchanced by about 1.5 times as compared with the nontreated eggs. In the eggs exposed to urethan–seawater for over 70 minutes many clear spots appeared throughout the cytoplasm. Simultaneously, the pigment granules, which had been embedded within the cortex, migrated to the inner cytoplasm and encircled a monastral centrosphere and clear spots. The clear spots were composed of microtubules much like cytasters, and in the central region of them centrioles were not yet found. The eggs in which the pigment granules disappeared from the cortex may be more susceptible to cleavage induction by succeeding hypertonic treatment.
Reversal of sexual induction in Volvox carteri by ultraviolet irradiation and removal of sexual pheromone
Authors: Kochert Gary , Crump William J.
Published: February 2005

Washing in fresh culture medium or short exposure to ultraviolet irradiation (UV) was found to reverse the action of the sexual pheromone produced by the green alga Volvox carteri. Induced gonidia which would normally form egg‐bearing females formed mainly asexual individuals in response to these treatments. The UV effect is strongly dependent on the stage of the life cycle at which exposure is given. Sexual induction in this organism requires early and continuous exposure to the sexual pheromone. The mechanism by which UV reverses sexual induction is not understood, but it could be caused by inactivation of the pheromone or by inactivation of a pheromone‐induced repressor of asexual characters.
Ultrastructural studies of mutant spermatozoids in ferns. I. The mature nonmotile spermatozoid of mutation 230X in Ceratopteris thalictroides(L.)Brongn
Authors: Duckett J. G. , Klekowski E. J. , Hickok L. G.
Published: February 2005

Electron microscopy reveals that nonmotility in the spermatozoids of mutant 230X of the fern Ceratopteris thalictroides results from highly aberrant flagella. With respect to its mitochondrial complement, amyloplasts, condensed chromatin within the nucleus and the multilayered structure (MLS), the mutation is almost indistinguishable from the wild‐type spermatozoids. In contrast to flagellar mutations in other organisms (man, mouse, Drosophila, Chlamydomonas), which principally affect the microtubules of the axoneme, the basal body cartwheel is lacking in 230X. In its absence, compound microtubules with shared walls are still present, but in highly disorganized arrays. Since the amount of polymerized tubulin in the spermatozoids of 230X is approximately the same as in the wild type, the mutation does not seem to affect microtubule synthesis or assembly. Centriolar cartwheels appear to be essential templates for the alignment of triplet and doublet tubules in regular radial arrays.

The MLS in 230X is almost normal, whereas the flagella are aberrant, indicating that there are two distinct functional classes of microtubules in archegoniate spermatozoids. In contrast to the helix of 3½ gyres found in the wild type, nuclear morphology in 230X exhibits profound distortions ranging from deep channels and holes to supernumerary attenuated arms. Parts of nuclei associated with the MLS are almost normal, but malformations are in variably associated with the presence of microtubules of the aberrant flagella that are in close proximity t o the nuclear surface. The shapes of the teratologies are directly related to the number and configuration of the adjacent perinuclear tubules.

From these findings, it is argued that microtubules have a crucial role in nuclear shaping in archegoniates; and that the precise form of the nucleus is closely related to the geometry and development of the MLS. On the other hand, it is difficult to envisage how microtubules growing in the chaotic arrays found in 230X could themselves generate shaping forces, More likely, the actual force‐generating system, situated in or near the nuclear envelope, has become misaligned and severely restricted by the perinuclear arrays of flagellar tubules, which function as cytoskeletal elements additional to those of the normal MLS.

Archegoniate plants are particularly advantageous for the detection of basal body mutants, since centrioles are absent from the mitotic apparatus. Cytological and hybridization studies of 230X affirm the nuclear basis of the mutation, and provide no support for the possible genetic autonomy of centrioles.
Quantitation of avian spermatozoan motility: Neurochemical regulation
Authors: Atherton R. W. , Cisson C. M. , Wilson B. W. , Golder T. K.
Published: February 2005

The hypothesis that motility of avian sperm is regulated by acetylcholine was examined by treating rooster (Gallus domesticus) sperm with choline analogs and paraoxon, an inhibitor of colonesterases. Acetylcholine chloride (AChCl) was most effective, acetylthiocholine iodide and butyrylthiocholine iodide were less effective, and choline chloride was ineffective in stimulating sperm motility. Histochemical localization of cholinesterase activity with the electron microscope showed enzyme activity to be associated with membranes of the head and within fibrillar components of the tail. Increasing concentrations of paraoxon decreased cholinesterase activity and increased sperm motility. The data provide evidence that the motility of avian sperm, like that of mammal and sea urchins, may be regulated in part by a system with similarities to the cholinergic neurotransmitter system.
The changes in sperm nuclei after penetrating fish oocytes matured without germinal vesicle material in their cytoplasm
Authors: Iwamatsu T. , Ohta T.
Published: February 2005

The processes occurring from sperm penetration to chromosome formation in the cytoplasm of Oocytes matured in vitro, after removal of the germinal vesicle (GV) and before hormonal stimulation, were observed with electron microscope. The dechorionated oocytes, matured without the participation of the GV material, responded to sperm penetration by initiating a cortical reaction within 20 seconds after insemination. The pentrating sperm nuclei transformed to male pronuclei with vesiculation of the nuclear membrane, chromatin decondensation, and formation of a pronuclear membrane. Before cleavage, however, no chromosome formation was observed in these oocytes. Instead, the fully grown pronuclei change to a picnotic chromatin mass without or with an only fragmented nuclear membrane, then disappeared. On the contrary, sperm nuclei that penetrated into the cytoplasm of naked eggs containing GV material during maturation underwent pronuclear and chromosomal formation. Judging from these observation in Oryzias oocytes, the GV material seems to be unnecessary for the formation of pronucleus from the compact sperm nucleus, but is essential for the process of chromosomal formation.