bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ovarian chromosome cycle in a mixed rat strain
Authors: Swezy Olive 
Published: February 2005

AbstractIn the ovary of the rat the ova arise by proliferations from the germinal epithelium, all cells of which are potential ova. This proliferation begins with the differentiation of the gonad, and may last as long as 369 days postpartum. The embryonic ovary is filled with ova which pass through the typical maturation phases. This continues until five days after parturition. These ova degenerate, none being found in the ovary of the twenty‐day rat. After the fifth day postpartum, nuclear development in the ova changes until, by the twentieth day, no typical maturation phases are present. With the degeneration of the embryonic ova the ovary takes on the adult structure.The ovary of the adult female rat shows a modified type of meiosis in the germ cells, while that of the embryo shows the typical phases, indicating that this is the primitive type, with the modified form an acquired characteristic.Ova in a single rat may show both twenty‐one and thirty‐one chromosomes.Follicle cells are formed from the cells of the germinal epithelium and, like the sex cells, may have both forty‐two and sixty‐two chromosomes in a single follicle. The lutein cells also show both forty‐two and sixty‐two chromosomes in a single corpus luteum. The chromosomes of the lutein cells enlarge with the expansion of the cell to a size greatly in excess of the chromosomes of the somatic cells. The theca interna is derived from the tunica albuginea.
A study of the function of the epididymis. II. The importance of an aging process in sperm for the length of the period during which fertilizing capacity is retained by sperm isolated in the epididymis of the guinea‐pig
Authors: Young William C. 
Published: February 2005

AbstractFollowing the isolation of sperm in the epididymides of male guinea‐pigs by the separation of this organ from the testis, the animals were found to remain fertile for periods varying from twenty to thirty‐five days, whether they were allowed to mate but once during this period, or five times during the period, or twenty times during the period. Motile sperm were found as long as fifty‐nine days after the operation. It was concluded, on the basis of these data, that an aging process which sperm isolated in the epididymis undergo is more important than the number of matings (up to at least nine or ten) in the determination of the period during which sperm motility is retained and in the determination of the period during which fertilizing capacity is retained.If the behavior of sperm isolated in the epididymides can be taken as an indication of the processes of sperm development which occur normally, the epididymis would seem to be an organ in which sperm may at one time be attaining an optimal functional state and may at another time be aging and becoming incapable of functioning. The possible significance of this suggestion for the rǒle of the epididymis in sperm development and for the history of sperm after they leave the testis is discussed.
The origin of neutral fats from the Golgi apparatus of the spermatid of the dog
Authors: Bell A. W. 
Published: February 2005

AbstractBy the use of a new technique it was possible to demonstrate the Golgi granules about the idiosome of spermatids and in the so‐called Golgi bead of the mature spermatozoon. Other osmiophile granules in the cytoplasm, assumed to be Golgi granules, aggregate during metamorphosis into groups which formed neutral fat spheres, giving stains with both sudan III and scharlach R. Evidence is adduced supporting the view that the Golgi apparatus is a lipin and probably a phospholipin. The fat spheres produced are probably a result of fatty degeneration in the residual body of the spermatid. They may also serve as the source of lipin in Popa's ‘Lipo‐gel’ phenomenon.
Photoreceptors in Mya arenaria, with special reference to their distribution, structure, and function
Authors: Light V. Earl 
Published: February 2005

AbstractExperimental studies on the responses to light in Mya arenaria L. indicate that photosensitive tissue is located somewhere near the inner surface of the siphon and that the siphon is sensitive throughout its entire length.A histological study of the siphon shows cells of a special type in the photosensitive region, which are most abundant where the inner surface of the siphon is most sensitive. They are found throughout the length of the siphon, just beneath the inner epithelial layer, around both the incurrent and excurrent siphons. They receive nerve elements from branches of sixteen large nerves.Each cell contains a characteristic inner structure, the optic organelle, composed of a rather large hyaline structure, the lens, which is surrounded by a network of nerve fibrillae, the retinella. Light rays, reflected from a flat mirror through the lens in these cells, are brought to a focus in the region of the retinella, irrespective of the direction of the rays.The cells are similar in structure and function to visual cells in leeches and photoreceptors in the earthworm. Available data indicate that they function as photoreceptors and that the fibrillae of the retinella are direct receptors of light stimuli.Pigment spots found in considerable number on the distal third of the siphon, and thought by some to be eyespots, are, owing to simulation of the background, probably protective in nature, rather than functional in photoreception.
The formation of the sex glands and germ cells of mammals. IV. Continuous origin and degeneration of germ cells in the female albino rat
Authors: Hargitt Geo. T. 
Published: February 2005

AbstractThe current view in mammals is that ova are formed in the embryo in large numbers and stored in the ovary as a reserve to be drawn on through adult life; they may persist for long periods ina latent condition, a few resuming active development at each recurring oestrous period; new ova are not and cannot be added.An alternative hypothesis has been presented by several authors: New ova are formed throughout life, from the embryonic period through the time of sexual maturity; each ovum so produced must at once begin its growth and development of die; long latency of oocytes and primary follicles is not possible and does not occur. There is a constant degeneration of most follicles, and only a few come to ovulation. A study of the albino rat presents evidence which is consistent with the second view and supports it more strongly that it does the older hypothesis. Similar evidence is found in other mammals. It seems probable that the newer hypothesis is the correct one, at least in some mammals; further investigation may show it to be of general application.
The natural history of Bugula flabellata at Woods Hole, Massachusetts, including the behavior and attachment of the larva
Authors: Grave Benjamin H. 
Published: February 2005

AbstractThe breeding season of Bugula flabellata extends from June 10th to November 15th. The young embryos develop in brood pouches (ovicells) and are finally expelled from the colony as swimming embryos. They come from the colonies at dawn or early morning. After a free‐swimming period of four to six hours, each larva becomes attached and after a profound metamorphosis which involves the loss of larval organs, it develops into the bryozoan colony by budding.The larvae at first are positive to light, but become negative before attachment. Their behavior is described in detail and the mode of attachment is explained.After the larva has become attached a period of rapid growth by budding ensues. The rate of growth is given in a table in which it is shown that the first individual of the colony is completed in two days and that a new series of buds is formed every two days. There are eight or ten individuals after one week and over a hundred in two weeks. In one month the colony is half‐grown and becomes sexually mature. A colony becomes senescent in three months, when it measures 112 to 134 inches in diameter.Younger colonies hibernate successfully and resume growth in early May, when new polypides are formed.
The arterial system of Palaemonetes
Authors: Brody Michael Steve , Perkins Earle Bryant 
Published: February 2005

AbstractColor changes in Palaemonetes had been found to be inhibited in the whole abdomen by occluding the dorsal abdominal artery. Inasmuch as these chromatic responses are brought about by means of circulating hormones, it should be possible, in view of early anatomical findings, for specific substances to reach the abdomen by way of the ventral abdominal artery which has been described for so many decapod crustaceans. This paper reports a degenerate ventral abdominal artery and a ventral continuation of the dorsal abdominal artery, the latter thus being distributed to practically the entire abdomen and therefore chiefly responsible for abdominal color‐change phenomena.A method is given for injecting the arteries of small crustaceans, and the entire arterial system of Palaemonetes is described and figured. Several hitherto unreported vascular structures are noted: a plexus of blood vessels surrounding the supra‐oesophageal ganglion, certain branches of the ophthalmic artery leading to the eyes, and various branches of the dorsal abdominal artery in the region of the telson and uropods. The forward flow of blood in the ventral portion of the abdomen in decapod crustaceans is held to be unique.
A histological basis to explain constant differences in action‐current response from certain points on the retina of the horned toad, Phrynosoma cornutum
Authors: Keeler Clyde E. 
Published: February 2005

AbstractThe retina of Phrynosoma cornutum bears fovea, pecten, and many varieties of cones. The light band visible in fresh retinae beneath the slit of the eyelid corresponds to a zone of action current responses characterized by a low ‘B’ rise (negative response of Chaffee.) The lack of response from pecten and fovea is due to leakage and failure to tap ganglionic fibers.Relief maps for ‘on’ and ‘off’ effects of the ‘B’ rise were prepared.Diagrams of retinal response in cross‐sections were compared with corresponding curves showing density of cone distribution. In general, the height of response is inversely proportional to the density of cone distribution.The potential change due to photochemical reaction in the average rod is on the order of 23 billionths of a volt for the ‘on’ effect and 11 billionths of a volt for the ‘off’ effect.
The morphology of Spironympha, with a description of a new species from reticulitermes hesperus Banks
Authors: Brown George V. E. 
Published: February 2005

AbstractSpironympha is discussed as valid genus. It was described by Koidzumi ('16); later it was redescribed by the same author as Microspironympha ('21). Therefore, according to the rules of nomenclature, it is Spironympha.The genus is compared with the related genera: Spirotrichonympha, Holomastigotes, and Microjoenia.Spironympha is characterized by four flagellar bands which are spirally wound around the anterior part of the body; these bands occur only in the anterior end, whereas in Spirotrichonympha they extend almost to the posterior end. The parabasals are few in number, and they are attached to the basal granules of the flagellar bands; the anterior end is clear and almost free from cytoplasmic granules; and there are twenty to thirty anterior flagella which are attached to the base of the centroblepharoplast or to the basal granules of the flagellar bands. An axostyle is present.No centrosome occurs within the nucleus, but the centroblepharoplast has this kinetic function.Spironympha ovalis is described as a new species. It is ovoid; the average size is 38 μ to 44 μ. An axostyle is present. The host is Reticulitermes hesperus Banks.
The evolutional significance of the chromosomes of Aphididae
Authors: Shinji Orihay 
Published: February 2005

AbstractAn investigation into the number of chromosomes in thirty‐seven species of Aphidiae belonging to twenty‐seven geaera has shown that there is but one sex chromosome in the male cells of all but one species of Aphididae. That exceptional species is Euceraphis betulae Koch.The number of chromosomes and body characters are so closely correlated that we can safely judge the evolutional scale of any aphid by its number of chromosomes.In Aphididae the least number of chromosomes seems to be the most primitive.The number of chromosomes varies with the genera. The highest number is 1811+ X = 37 chromosomes, the lowest being 211+ X = 5 (diploid in male).The increase in the number of chromosomes seems to have been brought about by transverse divisions of the primitive chromosomes.The genus Tuberolachnus with 311+ X = 4 elements (♂) represents altogether different chromosomes characters from the genus Pterochlorus with 8 elements.In the genera Periphyllus and Calaphis there are species with a smallm‐element which is bivalent.
The vacuome of the flagellate Chlamydomonas
Authors: Hall Richard P. , Nigrelli Ross F. 
Published: February 2005

AbstractA vacuome (‘Golgi apparatus’) consisting of small globular inclusions has been demonstrated in Chlamydomonas sp. These inclusions may be seen in the living, unstained organism; they are stainable vitally with neutral red; they have been stained vitally with neutral red and then blackened with osmic vapor under direct observation, and they have been impregnated by osmic and silver methods without previous treatment with neutral red.The reaction of these inclusions to the iodin test for starch suggests that they may play some rǒle, possibly one of storage, in the cycle of starch metabolism.
Notes on the postnuclear, acrosome‐seat granules, and ‘vacuome’ in Desmognathus fusca spermatogenesis
Authors: Gatenby J. Brontë 
Published: February 2005

AbstractThe acrosome in Desmognathus, Spelerpes, Plethodon, salamander, Amphiuma, etc., is attached to the nucleus in connection with an acrosome seat, which forms a shallow cup, traced back to a number of granules in the early spermatid. A postnuclear plate is present in the above‐mentioned urodeles, and is derived from a small number of minute granules which assemble in the spermatid and become fixed onto the nuclear membrane. The centrosomes of the spermatid are visible intravitam. The ‘vacuome’ is formed of minute neutral‐red‐staining globules embedded in the idiozome. No connection appears to exist between mitochondria and Golgi bodies, as is postulated by the vacuome‐chondriome hypothesis (Parat).
Insect development. II. Mitotic activity in the grasshopper embryo
Authors: Slifer Eleanor H. 
Published: February 2005

AbstractThe onset of hibernation in Melanoplus differentialis eggs kept at high temperatures is accompanied by a fairly abrupt cessation of cell division. The total number of mitotic figures present in the different individuals of a series of embryos of this grasshopper, from eggs kept for eighteen to twenty days at 25°C. from the time of saying, was found to vary between 1000 and 4400. In contrast to the conditions found in eggs of this age, embryos from eggs kept twenty‐seven days at 25°C., as well as those older and still in the hibernating state, contained few or no dividing cells. During the course of the work it was found that, in rare cases, hibernation failed to occur, a few or many of the eggs developed without a pause when kept at 25°C., and hatched at approximately the thirty‐eighth day. The detection of variations in the rate of mitotic activity over short periods, as originally planned, was found impossible, because of the comparatively small number of embryos used.
Studies on the comparative histology of the digestive tube of certain teleost fishes II. A minnow (Campostoma anomalum)
Authors: Rogick Mary Dora 
Published: February 2005

AbstractThis paper presents a study of the normal histology of the digestive tract of an herbivorous teleost, the minnow Campostoma anomalum (Raflnesque). The tunics of the buccal cavity, pharynx, esophagus, and intestine are described; particular attention is given to the mucosa because of the specializations occurring in that coat, such as taste buds, goblet cells, callous pad, etc. Because of the very decided anatomical and histological differences existing between the anterior and posterior regions of the pharynx, due to the presence of a callous pad and pharyngeal teeth, it has been deemed advisable to consider the pharynx as divisible into an anterior and a posterior region. Thyroid tissue was found in the submucosa of the anterior pharynx. No gastric epithelium was demonstrated, the ‘intestinal bulb,’ the only enlargement of the coelomic portion of the digestive tube, being lined with epithelium presenting only minor differences from that found in the coiled tubular intestine.
The ontogenetic history of the mitochondria of the hepatic cell of the white rat
Authors: Smith Dorothea M. 
Published: February 2005

AbstractThis work was designed to determine the ontogenetic variability of the morphology of mitochondria of the hepatic cell.The mitochondria of the cells of the hepatic diverticulum are minute spheres. These spheres enlarge, become associated, forming beaded filaments, which in turn become smooth filaments, the process culminating in the twenty‐day fetus. There is no individual or lobular variabillty in fetuses of a given length. One‐half day before birth the above process is reversed, so that separate spheres are found in the eight‐ to twelve‐hour young. This enlargement and enspherulation are accompanied by an accumulation of large quantities of glycogen. After this age, the spheres become associated into beaded filaments again and the glycogen disappears, the cycle ending at thirty‐three hours. From two to eight days of age there is great individual variability.Mitochondrial morphology characterstic of the adult is first found in the fourteen‐day young, when cells contain long, smooth or beaded filaments, rods, and spheres. There is no lobular variation as to types of mitochondria, but only in numbers, the cells around the central vein containing fewer mitochondria than other cells of the lobule. Variation between individuals after birth is due to something other than age, type of food, period of digestion, and length of starvation. Fat is formed within spherical chondriosomes.
Cytoplasmic structures in the ganglion cells of certain Orthoptera, with special reference to the Golgi bodies, mitochondria, ‘vacuome,’ intracellular trabeculae (trophospongium), and neurofibrillae
Authors: Beams H. W. , King Robert L. 
Published: February 2005

AbstractThe Golgi bodies of the nerve cells of the grasshopper are discrete elements composed of an osmiophilic cortex and an osmiophobic medulla. When seen in face, they appear ring‐like, semicircular, or crescentic. The osmiophilic portion is interpreted as the homologue of the classical Golgi apparatus and may under certain conditions be dissolved away, leaving clear spaces homologous to the canalicular apparatus (negative image of Golgi apparatus). When the osmiophilic portion is dissolved, the osmiophobic portion remains as a definite structure which apparently has no homologue in the classical Golgi apparatus. The mitochondria are granular, rod‐like, or filamentous and show no transformation into Golgi bodies. Neutral‐red bodies (‘vacuome’) of two kinds have been observed, neither of which is a constant preformed structure or has any relationship to the Golgi bodies. Prolongations of the capsule (trophospongium?) of the nerve cell penetrate into the cell approximately one‐third the distance to the nucleus. These are interpreted as supportive rather than nutritive in function. A basket‐like net of neurofibrillae surrounds the nucleus. It is suggested that the networks described as Golgi apparatus in certain invertebrate nerve cells may really consist of these neurofibrillae.The conclusion of Parat that Golgi material consists either of mitochondria or ‘vacuome’ is rejected. The idea that all structures in the living cell which stain with neutral red (‘vacuome’) are homologous is also rejected.
The nutrition of glochidia during metamorphosis. A microscopical study of the sources and manner of utilization of the nutritive substances
Authors: Arey Leslie B. 
Published: February 2005

AbstractPart of the nutriment of metamorphosing glochidia is supplied by the cellular host tissue, bitten by the larvae during attachment. Some of this is taken up piecemeal by the mantle cells and digested intracellularly. The coarse granules that first pack the mantle cells are apparently the precursors of a digestive secretion, some of which escapes into the mantle cavity. Here it also causes the prompt dissolution of additional utilizable host tissue.Another source of nutriment is furnished by the provisional larval adductor muscle which undergoes degenerative changes in situ, then fragments, and finally is carried away bit by bit by amoeboid cells. These turn over their muscle content to the larval mantle, where the particles are further reduced beyond recognition. The mantle remnant itself is finally sacrificed and doubtless becomes an additional source of nutriment.The gut serves as an organ of nutrition throughout the last two‐thirds of the parasitic period. It appears to admit and digest pieces of the adductor muscle and certain unidentified particulate matter. In addition, the gut, like the definitive mantle and other organs, doubtless absorbs tissue transudate from the host.Special vascularization of the host tissue to facilitate the passage of nutriment from host to parasite does not occur, yet there is no reason to doubt that an appreciable part of the larval nutrition results from transuding tissue juices.
Coordination of ciliary movement. II. The effect of temperature upon the ciliary wave length
Authors: Lucas Alfred M. 
Published: February 2005

AbstractThe ciliary wave length is a constant in the temperature range of 10° to 30°C. and in Modiolus demissus has the average value of 13.1 μ. Comparison of these data for ciliary coordination with those of nerve conduction probably indicates that the two physiological processes possess certain properties in common. The cells which bear the cilia are 12.75 μ long and the variation in ciliary wave length and cell length is about the same, which may indicate a possible cytophysiological relationship between the two.
Comments on the origin of the midgut in insects
Authors: Richards A. Glenn 
Published: February 2005

AbstractReviews the question of the origin of the midgut of insects with its diverse appearances and interpretations. Without doubt the midgut epithelium in some insects is derived from the lower layer, but in other insects from the tips of the stomodaeal and proctodaeal invaginations. The question of its origin seems to be “a function of the position within the whole,” and best understood from a standpoint of the time of determination of the parts involved. Maps illustrating the prospective significances of the principal types are included and discussed.