bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations on the fat‐body in Hymenoptera
Authors: Schmieder Rudolf G. 
Published: February 2005

AbstractAn histological and cytological study of the postembryonic history of the fat‐body in Pteronidea ribesi (Scopoli) and Diphadnus appendiculata (Hartig) (both Tenthredinidae) and in Macrocentrus ancylivora Rohwer (Ichneumonidae).The two principal components of the fat‐body are the urate‐storing excretory cells and the fat‐cells.The development and behavior of the excretory cells, especially during the metamorphosis, are described, and in Pteronidea their origin is traced to leucocytes which have become associated with the fat‐cells.In the albuminoid inclusions found in the fat‐cells two types of substance are distinguished: (a) a basophile material, of nuclear origin, which appears only during the metamorphosis; (b) an acidophile material which appears already during the early larval stages in Macrocentrus, but in Pteronidea is formed only during the metamorphosis and in association with the basophile material. It is thus found that albuminoids formed slowly during larval life may exist from the beginning in the form of acidophile spheres, as occurs in Macrocentrus. But those formed rapidly during the metamorphosis, in all the forms studied, are formed in association with a basophile material derived from the nucleus.The significance of intracellular changes during the metamorphosis is discussed, and the final disposition of the cell inclusions as well as of the fat‐cells themselves is described.
A sexually mature turbellarian resembling Müller's larva
Authors: Heath Harold 
Published: February 2005

AbstractThis paper deals with the description of an organism, externally resembling Müller's larva among the polyclads, collected in the plankton of Monterey Bay, California, during the spring and summer months. Internally, the organization of the various systems is unique. In some respects it bears a certain resemblance to a polyclad in early stages of development; in other regards it approaches the rhabdoceles, more particularly the Acoela. Its more exact relationships are obscured by the fact that, although the larger specimens are not more than 0.7 mm. in length, the sex organs, both male and female, are fully developed and functional. Furthermore, the plan of these systems is unlike that of any turbellarian hitherto described. Whether this organism represents a case of paedogenesis or is a fully developed adult is unknown at present, but in any event the various systems are described and an attempt is made to give it a fairly definite systematic position.
The septomaxillary. I. In the amphibia urodela
Authors: Lapage Enid Oldham 
Published: February 2005

AbstractThe septomaxillary bone is described in the various families of the urodeles in which it occurs. Its identity as a hitherto unrecognized cartilage bone of the skull is established and its close relationship with the nasal muscles followed through the group. Its presence or absence, which is found to be another criterion for the recent classification of the urodeles as proposed by Dunn and Higgins, is correlated with the development of the accessory dilatator muscle, since it occurs only in groups where this muscle attains an appreciable size.
The morphology and physiology of the hepatopancreas of Cambarus virilis
Authors: Dorman Henry P. 
Published: February 2005

AbstractThe relation of the hepatopancreas to the pyloric stomach and its physiologic histology were studied. The organ consists of two lobes, united ventrally, which lie along the cardiac and pyloric stomachs and the intestine. Primary and secondary lobulations (acini) are present, and the entire organ is a system of anastomosing tubules (lumina). The tubules progressively converge and form a duct in each lobe which leads ventrolaterally into the pyloric stomach.Each acinus consists of a single layer of hepatic and pancreatic cells supported by a basement membrane, and the interacinar spaces are the seat of fibro‐elastic tissue and phagocytic cells. The supporting tissue is laminar with that of the stomach. The arterial capillaries, composed of endothelial cells, lie in the interacinar spaces. The blood supply is by way of the basement membrane to the cells.The hepatic cells of specimens collected in September bear little fat; cells of June specimens are laden with fat. Glycogen is deposited in the hepatic cells; there is no difference between the quantity found in September and in June. The hepatic cells probably contain biliverdin. Chemical analysis indicates the presence of trypsin, amylase, and lipase.A review of the literature and a discussion of homologies with reference to the vertebrate liver are given.
Variations in chromosome number in the spermatogenesis of Philosamia cynthia
Authors: Dederer Pauline H. 
Published: February 2005

AbstractA study of spermatogenesis was made on four groups of a pedigreed strain of the moth Philosamia cynthia, and the results were compared with spermatogenesis in the wild material.Deviations from the normal number of chromosomes were observed in two groups. In some individuals the haploid number was 12 instead of 13. Giant spermatocytes were also observed with twenty‐four chromosomes. In other individuals, two haploid numbers, 13 and 14, occurred in the same testis.The twelve‐chromosome condition is due to linkage of two chromosomes during the late prophase of the primary spermatocyte. The double chromosomes thus formed appeared to divide equally in both divisions. The origin of the fourteenth chromosome was not determined.Correlation of the genetic and cytological data indicates the restriction of aberrant chromosome complexes to two of the four groups and the regularity of the twelve‐chromosome complex in certain families, suggesting the conclusion that a new strain arose in the pedigreed material with regard to chromosome variability and that the twelve‐chromosome condition is a well‐defined characteristic, partly established in some families and probably fully established in others.
The significance of the asymmetry of the ovaries of the fowl
Authors: Brode Malcolm D. 
Published: February 2005

AbstractA chronological investigation of the histological condition of the right ovary of the domestic hen from embryos of nine days' incubation to adults of eighteen months was made. A rudiment of the right ovary is found at all times. Its composition is variable. Sixty‐one per cent of the rudimentary ovaries contained medullary tissue only. Thirty‐nine per cent had rudiments of cortex, in addition. The occurrence of cortical rudiments in embryonic stages is the probable basis of ovarian follicles found in the rudimentary right ovaries of adults. Primordial germ cells persist in the medullary tissue until three weeks after hatching. They subsequently appear to atrophy. The medullary cords persist through the entire period either as distended tubules or as solid cords of modified epithelial cells. Remnants of the right mesonephros persist as tubules and connect with the gonad by rete tubules. The mesonephric duct maintains a patent lumen.
Ecological studies of the seasonal distribution of protozoa in a fresh‐water pond
Authors: Wang Chia Chi 
Published: February 2005

AbstractThis study deals with the seasonal distribution of protozoa (February, 1927, to February, 1928) in correlation with seasonal fluctuations of temperature, hydrogen‐ion concentration, and the relative amounts of dissolved oxygen and other gases in a small fresh‐water pond. Twenty‐seven species of Sarcodina, thirty‐one species of Mastigophora, and 109 species of Infusoria were recorded in the surface water of the pond.As found especially for Mastigophora and Infusoria, the number of species is inversely correlated with the abundance of individuals in the seasonal distribution.Higher temperatures probably accelerated the rate of reproduction, since the seasonal maxima for most of the species were recorded in warmer weather.Colonial flagellates and Zoochlorellae‐bearing ciliates seemed to be favored by higher oxygen content, with a simultaneous abundance of volatile acids, especially CO2. Although hydrogen‐ion concentration was limited between 6.2 and 7.05, it was probably one of the factors influencing protozoan distribution, since several species disappeared when the lowest pH was recorded. Sunlight is one of the important factors in bringing certain heliotropic protozoa to the surface.The seasonal maxima of many of the protozoa occurred during September and October, 1927, when most of the observed physical environments seemed much more favorable than in other months.
On the development of imaginal buds in normal and mutant Drosophila melanogaster
Authors: Chen Tse‐Yin 
Published: February 2005

AbstractDefinite information concerning the time of development and location of the different imaginal discs of Drosophila melanogaster was needed in order to interpret especially the gynandromorphs, mosaics, and intersexes that have been extensively reported in cultures of this fly. This information was also desirable for many of the mutant types. It was not known, for example, when an organ was reduced or absent, whether its imaginal disc showed a corresponding reduction, or whether it was full size in the larvae and pupae, and failed to carry through to the later stages.Three mutant types with eyes smaller than those of the wild type, namely, lozenge, bar, and eyeless, were examined. It was found that there is a corresponding difference in size as far back as the imaginal disc could be detected. Similarly for the two mutants, vestigial and no‐wing. Conversely for the mutant, bithorax, in which the metathorax is larger than the normal and has assumed many of the characters of the normal mesothorax, the imaginal disc was correspondingly enlarged.It follows that the effects of the mutant genes for these characters can be observed in the very earliest condition of the imaginal disc.
Cytological studies on the spinning glands of platyphylax designatus walker (Trichoptera): Respective rôles played by the nucleus and the golgi apparatus during secretion
Authors: Beams H. W. , Wu C. F. 
Published: February 2005

AbstractIn sections the protoplasm of the spinning gland of Platyphylax designatus Walker appears to be a syncytium with large, branching nuclei, which contain both nucleoli and chromatin granules embedded in a delicate linin reticulum.In the normal gland the nucleus is sharply marked off by a nuclear membrane from the granular, homogeneous cytoplasm. The Golgi apparatus appears as rings, loops, or comma‐like structures, evenly distributed and without orientation to the nucleus or lumen of the gland.The nucleoli first increase both in number and size within the nucleus, then migrate out into the cytoplasm, where they undergo further growth, and finally are dissolved and passed out into the lumen of the gland as liquid secretion.Small vacuoles appear near the periphery of the gland in early periods of activity.In glands active for forty‐eight hours all stages of the secretory process may be seen.In glands active for longer periods only vacuoles are present which we interpret as the remains of the secretory inclusions. There is a progressive decrease in the nuclear content of the nucleus.Throughout the activity of the gland the Golgi apparatus changes little from the normal condition, both in form and distribution. As activity progresses, the bodies become smaller and slightly more dispersed. No relation of Golgi apparatus to the secretory phenomenon is apparent.
A study of the function of the epididymis. I. Is the attainment of full spermatozoon maturity attributable to some specific action of the epididymal secretion?
Authors: Young William C. 
Published: February 2005

AbstractDuring the past few years many functions have been assigned to the epididymis which have been supplementary to its rǒle in sperm storage and to its secretory activity. One of these, the suggestion that sperm attain full maturity and are strengthened in consequence of some action of its secretion, has been reinvestigated as the first part of a study which is intended to include other aspects of the problem.No evidence in support of the theory was obtained from a series of experiments on various mammals representing a repetition and extension of earlier work. On the contrary, the strengthening and attainment of full spermatozoon maturity would seem to be the outcome of changes which are inherent in the sperm themselves. It is suggested, therefore, until other aspects of the subject can be reinvestigated, that the epididymis is simply a reservoir for sperm in which the processes of sperm development which start while they are still contained in the testis are free to continue because of the favorable environment present in the epididymis.
The anatomical qualities of the liver during the various stages of its functional activities
Authors: Forsgren Erik 
Published: February 2005

AbstractThe liver has a rhythmic function with alternating assimilatory and secretory stages. The height of the assimilatory stage in rabbit's liver is characterized by the following qualities: All the cells are usually expanded and contain much glycogen and few bile components. The bile capillaries are narrow and generally empty. The glycogen content is high (about 13 per cent); the total glycogen weight is also high (about 17 grams). The liver has a relatively heavy weight (about 140 grams), a large volume, notably firm consistency, and a light brown color.The secretory stage at its height has the following characteristics: All cells are shrunken and are rich in bile components, but contain little glycogen. The bile capillaries are expanded and filled with secretion (fixation with barium chloride). The glycogen content is low (about 1 per cent), and the total glycogen weight is also low (about 1/2 gram). Weight of liver low (about 50 grams). Volume small and consistency fairly flaccid. Color dark reddish brown.Between these two extremes are various intermediary stages. Such variations as these probably occur during the normal functioning of the liver in man and also in other animals.
The structure and chromosomes of three gynandromorphic katydids (Amblycorypha)
Authors: Pearson Nathan E. 
Published: February 2005

AbstractThe external genitalia and the internal reproductive organs are described. Compound gonads, with a normal development of testicular and ovarian tissues, are found in the positions of the gonads of normal individuals. The genital ducts arise in both types of tissue and serve as common ducts.It is demonstrated microscopically that the male tissue has one and the female tissue two sex chromosomes. The diploid number (or nearly so) is present in both tissues. This is the constitution of the normal sexes.The origin of the gynandromorphs is accounted for by assuming either the theory of dispermy in the binucleated egg or chromosomal elimination.
The embryological basis of size inheritance in the rabbit
Authors: Castle W. E. , Gregory P. W. 
Published: February 2005

AbstractA comparative study of the embryology of the rabbit in races of large and small adult size shows a consistently more rapid rate of cell multiplication and of increase in mass in large‐race embryos than in those of small race.This more rapid rate of growth is transm tted by and influenced equally by sperm and egg cell, as is shown by the results of reciprocal crosses.Rate of differentiation is independent of rate of growth and unaffected by it. Consequently, embryos of the large race have attained greater size than those of the small race at corresponding stage of differentiation.The fundamental difference in rate of growth is already in evidence in forty‐eight‐hour embryos and becomes increasingly clear at later stages. Embryos produced by the large race have undergone about one more cell division at forty‐eight hours after mating and so are approximately in the thirty‐two‐cell stage when embryos of the small race are in the sixteen‐cell stage.
A cytological study of the proximal and distal tubules of the mesonephros of Necturus maculosus. (Under normal and experimental conditions)
Authors: Curry Laliah F. 
Published: February 2005

AbstractThe purpose of this study was to determine whether structural elements of the cytoplasm can be demonstrated to be specifically concerned with certain physiological processes that are experimentally induced in tissue at the time of fixation. The methods for bringing into view variations in cell structure correlated with cell activity were as follows: the increase of the process of secretion by subcutaneous injection into the living animal of phenol red and of urea; the increase of the process of reabsorption by injection of glucose: the inhibition of reabsorption of sugar by injection of phlorhizin.Variations of the same magnitude in the form, position, quantity, and interrelationships of granules, globules, chondriosomes, and Golgi substance were found to occur in normal untreated animals and in those treated experimentally. Some evidence was found that in cells of the proximal tubule a characteristic form of Golgi body appears which seems to be correlated with increased reabsorption of sugar.
Periodic reversal of heart action in the silkworm moth and pupa
Authors: Gerould John H. 
Published: February 2005

AbstractDirection of peristalsis of the dorsal vessel in prepupa, chrysalis, and adult of Lepidoptera is not constantly forward; phases of forward peristalsis alternate with phases either of backward peristalsis throughout the whole dorsal vessel or of diverging waves originating in the third to fourth abdominal segments, proceeding backward and forward. Periodic reversal in the silkworm begins twenty‐four hours after spinning, forty‐eight before pupation. Pupation occurs during a vigorous backward phase. Soon after pupation, and sometimes during pupation, backward phases consist of diverging waves. Later, and in the adult, complete reversal intermittently occurs. Backward phases in the pupa are long (e.g., fifteen minutes), the average rate slow and variable, quickening at eight to ten days to that of the adult. Any long backward phase shows a gradual slowing down, except approaching pupation when the pulse quickens to equal that of forward beating. Average rate of forward beating is constant at constant temperature, but absolute rate in a long phase gradually slackens. Pauses (sometimes one and one‐half hours long in older pupae) often follow forward phases. Alternating phases in the adult, compared with the pupa, are short, about one minute and usually less than one hundred beats. In old moths the phases become still shorter, often being reduced to single beats. Opposing waves occasionally conflict. Periodic reversal occurs for hours after excision of the dorsal wall with the pericardium and heart. As in ascidians, back pressure cannot explain reversal.
Some phases in the embryonic development of Diacrisia virginica fabr. (Lepidoptera)
Authors: Johannsen O. A. 
Published: February 2005

AbstractThe cells of the blastoderm which are to form the serosa are two‐ to four‐nucleate; the smaller cells of the embryonic rudiment, uninucleate. The band‐like embryonic rudiment encircles the yolk at the equator of the egg. The amnion does not begin to form until after the serosa completely covers embryo and yolk. The epithelium of the midgut arises from cells situated at the tips of stomodaeum and proctodaeum. These cells, though not differentiated from adjacent ectoderm at the time of the invagination, are nevertheless interpreted as part of the preprimordium of the endoderm. In the eighty‐four‐hour stage a fold of amnion grows over the dorsal side of the embryo, entirely covering it in the course of the next few hours. A portion of the amnion thus forms the dorsal wall of the embryo. At the completion of the amnion the embryo rotates so that its ventral side is directed toward the egg center. The amnion raptures just before the larva begins to feed on the yolk which still remains around it. The serosa is consumed before hatching, which takes place about five and one‐half days after deposition.
The formation of the sex glands and germ cells of mammals. III. The history of the female germ cells in the albino rat to the time of sexual maturity
Authors: Hargitt Geo. T. 
Published: February 2005

AbstractThe entire ovary, including its germ cells, is produced by a local proliferation of peritoneal cells. The germ cells of the embryonic ovary grow, divide, become grouped into nests, pass through synaptic changes, and become primary follicles by three days after birth. At that time, growth of all the ova and follicles begins, and this results in a normal maturation, then a degeneration of all the ova by about thirty‐two days after birth; few, if any, of the original germ cells remain after this degeneration. About twenty‐three days after birth, there begins a great activity of the germinal epithelium in forming new ova, reaching its maximum between thirty‐six and thirty‐nine days, but continuing into the adult animal.The definitive ova of the adult are transformed peritoneal (germinal epithelial) cells formed anew during the late youthful and adult life. This occurs chiefly by a local enlargement of single germinal epithelial cells which become surounded by follicle cells and push into the ovary; there is also the production of ova from ingrowing cords of the surface layer of the ovary. The original germ cells pass through synapsis and other meiotic changes in late embryonic and early postnatal periods, but these all degenerate; synapsis cannot be distinguished later than three days after birth. But it is possible to follow, in young and adult ovaries, the transforming germinal epithelial cells into ova which pass through normal maturation and ovulation; therefore, these must be considered as true ova, which they are in fact, even though synapsis cannot be observed in their history.
Cytological studies on the spinning glands of the larva of Galleria mellonella: Respective rôles played by the nucleus, the Golgi apparatus, and the mitochondria during secretion
Authors: Wu Chao‐Fa 
Published: February 2005

AbstractSpining in Galleria begins shortly after hatching and continues throughout larval life. The gland cells secrete continuously, irrespective of the act of spinning.The nucleus plays a direct and an importnat rôle in silk secretion by the migration of nucleoli into the cytoplasm, where they enlarge and synthesize a fatty material in the center; the fatty material is transformed into a non‐soluble basophllic substance, which then changes into the secretory product in its final form. The processes of converting the fat into non‐soluble substance and of converting the latter into the secretory product progress inwardly from the periphery of each secretory body. The secretory bodies or masses of secretory material break up into smaller and smaller masses and eventually into a fine dispersed state before their entrance into the lumen of the gland.The mitochondria are granular in the cells of the conductive portion and filamentous in those of the reservoir and secretory portions of the gland. In the secretory portion they are orientated with the long axis toward the gland lumen. Their rǒle in silk secretion is negligible or at most a minor one.The Golgi apparatus is in the form of discrete ring‐ and half‐ring‐shaped bodies and remains so during all stages of secretion. If it plays any rǒle in silk secretion, the fact has not been detected by the author.