bluuebunny/crossref_metadata_2025_split huggingface dataset:
The structure of the testis and movement of sperms in chortophaga viridifasciata as demonstrated by intravitam technique
Authors: Payne M. Anthony 
Published: February 2005

AbstractBy means of the ‘intravitam technic’ developed by Baumgartner and Payne (1931), the mature or maturing sperm of Chortophaga viridifasciata have been traced from the follicle of the testes in the male to the locus of fertilization in the female. The sperm aggregated into bundles, and held tight by a hyaline cytoplasmic cap, spiral up the follicle, turn and spiral back to the vas deferens by means of a periodic lashing and writhing of the sperm tails.The genital tract is described briefly. In the vasa deferentia and storage tubules, the sperm bundles are usually in a quiescent state, having been inactivated most probably by secretions from the tubules.Peristalsis and currents in the fluid contents of the tubules move the inactivated sperm from the vesicles of the male to the seminal receptacle of the female, where the cytoplasmic caps gradually disintegrate. This permits individual sperm to pass down the seminal duct and fertilize the ovum just before oviposition.Single photomicrographs and a series of photomicrographs show the sperm in various parts of the genital system and making actual progress up a follicle. A stained preparation was used for only one of the photos. The other nineteen are from living unstained tissue. The intravitam observations are, most probably, more ‘vital’ than any heretofore recorded.
An anatomical study of the furless condition in rabbits
Authors: Drapeau Elizabeth East 
Published: February 2005

AbstractA histological study of Hammond's simple recessive ‘furless’ rabbits was made from many series of sections taken from the skin of both the normal and furless rabbits of several pertinent ages.It was found that the external absence of under‐hair or fur exists because of a failure of the hairs of these follicles to erupt. This failure is due to a premature keratinization which first affects the sebaceous glands and then the inner epithelial sheath. The resulting abnormal channel allows an erratic escape, especially of the regenerating hair above the incomplete inner sheath into the surrounding connective tissue, where the escaped part of the hair atrophies. The final condition shows an inflammatory reaction in the areolar tissue here. There is no check on the growth from the bulb of the root. Other elements of the skin verify this excessive keratinization.The cause of the abnormal metabolic changes conceivably lies in an inadequate tissue supply of oxygen or nutrition. The regulator may be the sympathetic system directly or indirectly (by hormone action), or it may be an inhibitor resident in the integument itself.
Viviparity superimposed upon ovo‐viviparity in the goodeidae, a family of cyprinodont teleost fishes of the Mexican Plateau
Authors: Turner C. L. 
Published: February 2005

AbstractThe Goodeidae are a family of cyprinodonts containing about nine genera and twenty‐six species. They are confined exclusively to the Mexican Plateau and to streams in the immediate vicinity. All are viviparous. Fertilization is internal. The eggs are extremely small and contain very little yolk. The embryos are retained in the ovarian follicles until the yolk is practically absorbed, in the meantime developing unique absorptive organs in the form of extensive ribbon‐shaped proctodaeal processes. The embryos are evacuated into the intra‐ovarian cavity where they are retained for several weeks, during which time the proctodaeal processes become extended. The ovary becomes a nutritive organ and produces secretions which are discharged into the intra‐ovarian cavity and absorbed by the embryo through their unique processes. The processes differ in form, number, and histological structure, but are specific in their peculiarities for each species. These specific differences, together with marked differences in the ovary, will furnish a basis for a re‐classification of the genera and species of the family. A comparison in made between this family and the other ovo‐viviparous and viviparous cyprinodonts, on the basis of which it is concluded that the Goodeidae have arisen separately from an ovo‐viviparous ancestor, which in turn was derived from an ovo‐viviparous type. A comparison is also made between the peculiarities of reproduction in this family and those of other viviparous teleosts.
Localization of mineral ash in the organelles and cytoplasmic components of paramecium
Authors: MacLennan R. F. , Murer H. K. 
Published: February 2005

AbstractParamecium caudatum was studied by micro‐incineration, by stained control sections, by vital staining, and by osmic impregnation. It was found that a slow initial heating and a slow cooling after incineration greatly reduce the amount of distortion and shrinkage in the incinerated specimens. Most of the cytoplasmic components and organelles, including vacuome, chondriome, cilia, and basal granules, trichocysts, food vacuoles, and the nuclei, could be identified by their ash. No ash is found in the pellicle and only a small amount in the hyaloplasm. None of the osmiophilic components such as granules or the walls of the contractile vacuole could be identified in the incinerated specimens with certainty. The larger amount of ash in the endoplasm as compared with the ectoplasm is due to the large number of granules in the former region. The nucleus and some of the granules near the nucleus show traces of iron.
Studies upon regeneration. I. The constrasting powers of regeneration in planaria and procotyla
Authors: Curtis Winterton C. , Schulze Lula M. 
Published: February 2005

AbstractWhen sexually mature Procotyla fluviatilis Leidy (commonly but erroneously known as Dendrocoelum lacteum) are cut transversely into head, pharyngeal, and tail pieces of about equal length, the head and pharyngeal pieces fail to regenerate in a large percentage of cases and tail pieces never regenerate. When regeneration occurs in head and pharyngeal pieces it is somewhat slower than in similar pieces of Planaria maculata Leidy and Planaria agilis Stringer with which comparisons were made. Cutting mature Procotyla into larger numbers of pieces usually results in death of all, although smaller pieces from prepharyngeal regions sometimes regenerate. Juvenile P. fluviatilis have greater powers of regeneration, as shown by cutting head and pharyngeal regions into greater numbers of pieces, but tail pieces do not regenerate. These observations confirm and extend those of earlier investigators. Such a restricted power of regeneration contrasts with well‐known powers in P. maculata and P. agilis. Counts of formative cells, from which new parts arise in all three species and which are regarded by the authors as a persistent embryonic stock, indicate about 8.5 such cells in P. maculata to 1 in P. fluviatilis per unit area. It is concluded that regeneration in planarians is correlated with numbers of such formative cells and that histological factors are no less important than physiological ones. The paper is preliminary to a study of effects of x‐rays upon regeneration.
Staining reactions of protoplasm and its formed components. A cytological and biochemical study
Authors: Jeffers Katharine R. 
Published: February 2005

AbstractChemical analyses of the lipoids in fresh and autolyzed pancreas of the cat have been correlated with the staining reactions of sections of this organ preserved by three cytological methods. Quantities of total fats and of phospholipins, the iodine numbers of total fats and of phospholipins, and the free fatty acid numbers were determined. None of the methods of fixation used reveals the total fat content of the tissue. The intensity of staining of material fixed by Helly's method and stained with acid fuchsin is dependent on the phospholipins of the tissue, but the exact nature of the relationship is not certain. The intensity of staining of material preserved by Champy's method and stained with acid fuchsin can be correlated with the iodine number of the phospholipins of the cells. The degree of blackness of sections preserved by the Kolatchev‐Nassonov method can be correlated with the iodine number of the phospholipins of the cells. The free fatty acid content is probably also a significant factor. The methods demonstrate lipoids qualitatively rather than quantitatively. Only physiologically similar cells may justifiably be compared by the cytological methods studied.
Somatic mitoses of Drosophila melanogaster
Authors: Kaufmann Berwind P. 
Published: February 2005

AbstractThe chromosomes of D. melanogaster have been followed through the entire cycle of mitosis in ganglion cells. Primary constrictions exist at about the middle of the second and third chromosomes, at a sub‐median position in the Y, at a sub‐terminal in the X, and probably also at a sub‐terminal position in the fourth chromosome. Secondary constrictions, in addition to those reported by Bridges, are sub‐terminal in the arms of the second and third chromosomes. A pronounced sub‐median secondary constriction in the left limb of the second chromosome offers a criterion for distinguishing between the second and third chromosomes, and between right and left arms of the second chromosome. The proximal secondary constriction in the X‐chromosome and that in the short arm of the Y are associated with the normal development of the nucleolus. Anaphase chromosomes are longitudinally double, the split following the turns of the chromonemata. Metaphase and anaphase chromosomes are essentially isodiametric from end to end, except at the constrictions or indentures. Somatic pairing of chromosomes reaches its maximum expression during late prophases, both in male and female ganglion cells. The four chromatids of the tightly appressed homologues open out in two planes giving distinct chiasma‐like configurations. Separation of the paired chromosomes is completed in late prophase, so that at metaphase the homologous chromosomes are not in contact.
The development of the thymus bodies in necturus maculosus
Authors: Webster W. D. 
Published: February 2005

AbstractThe primordia of the thymus bodies in Necturus begin to form in 7‐mm. embryos. These structures arise as clumps of entodermal cells on the posterior dorsal portion of the first four visceral pouches; the first or last pouch, being rudimentary, fails to form such a primordium. All except the first of these primordia lose their connection with their respective pouches in the 16‐mm. stage and lie free in the surrounding connective tissue. The primordium on the first pouch begins to show degenerative changes during that stage, losing connection with its pouch in the 23‐mm. stage, finally to disappear altogether in 30‐mm. specimens.The three remaining bodies continue to grow, but the second and third outstrip the fourth in development and begin to form Hassall's corpuscles in 32‐ to 34‐mm. stages. Sections of 30‐mm. Necturi show a few of these corpuscles fairly well developed and containing a faintly staining secretion. The fourth body remains relatively small a long time, not showing the Hassallian cysts until the animal is 60 mm. long. By shifting of positions and increasing in size, the three bodies come to lie in proximity, one behind the other, to form the definitive thymus gland of the adult. The gland lies embedded in the heavy musculature on top of the head in front of the gills.
Chemoreceptors of blowflies
Authors: McIndoo N. E. 
Published: February 2005

AbstractThis paper deals with the morphology of all the so‐called gustatory and olfactory organs of blowflies, and describes tests conducted to determine whether these insects taste with their tarsi and smell with their antennae and palpi. Antennae bear two types of so‐called olfactory hairs, while palpi bear only one. With the aid of an olfactometer it has been shown that antennae and palpi do not bear the olfactory organs.In order to explain the proboscis response, described by Minnich, it is not necessary to assume that tarsi bear gustatory organs, because: (1) a tarus bears no sense organs, except nine olfactory pores; (2) it is almost impossible to wet the tarsi with water or sugar water; and (3) when flies were in the proper nutritive condition and liquids were about 3 mm. from the tarsi, the insects were induced by a special method to exhibit the proboscis response. It was further clearly demonstrated by a similar method that tarsi can easily distinguish between chemically pure saccharose water and distilled water when these liquids are about 3 mm. from the tarsi. The responses, obtained by any method, are caused by two stimuli, one mechanical and the other olfactory. The act of touching the feet produces the initial stimulus and brings the liquids almost in contact with the olfactory pores on the tarsi.
Intravitam studies on the hemipteran, Leptocoris trivittatus. A description of the male reproductive organs and the aggregation and turning of the sperms
Authors: Payne M. Anthony 
Published: February 2005

AbstractA study of the male reproductive organs of a hemipteron, Leptocoris trivittatus, has been made. The genital system, which consists of fan‐shaped testes; the vasa deferentia, to which a single pair of accessory glands are attached; ejaculatory ducts and the copulatory apparatus, is described and photomicrographs of consecutive parts presented.Then an analysis of the method of aggregation and turning of the sperms is made by means of intravitam technic. Aggregation and turning commence in the early spermatid stage. A spherical cyst forms, the tails first grow centripetally and then push out toward the lower end of the cyst. This line of growth in the cyst moves the head ends of the spermatids to the upper end where aggregation gradually takes place.The cysts spiral up and across the follicles, the moving force being, probably, the elongating tails. Later they spiral down the follicle, development progressing rapidly. The descending bundles are mature sperm, held together by a cytoplasmic cap.The accessory gland secretes a milky substance which probably activates the sperm at a later stage. Peristalsis occurs in the wall of the gland and duct.The process of massing sperm into bundles before copulation insures effective translocation. Then peristalsis and movement of tubular fluids carry the sperm down the duct to the copulatory apparatus.
Somatic synapsis in chironomus, with special reference to the individuality of the chromosomes
Authors: King R. L. , Beams H. W. 
Published: February 2005

AbstractThe nuclear band of the cells of the salivary glands of Chironomus larvae regularly consists of four segments or chromosomes. Each of these may be recognized by its characteristic distribution of chromatin discs of various sizes. When nucleolar elements are present they have a definite location in relation to the chromation discs of a certain chromosome. The diploid number of chromosomes is eight; therefore, the four segments in the cells of the salivary glands represent four pairs of homologous chromosomes in somatic synapsis which here is not a simple approximation but an accurate pairing part by part of the homologous chromosomes.
‘The Linea masculina,’ a new secondary sex character in Salientia
Authors: Liu C. C. 
Published: February 2005

AbstractA hitherto unknown secondary sex character in male frogs consists of a series of connective tissue bands which extends the entire length of both layers of the Obliquus muscle, at both their dorsal and ventral borders. Extensions of the ventral bands may be carried inward toward the midline at certain of the inscriptiones tendinae. These bands are named the Lineae masculinae. They are clearly visible in specimens from which the skin has been removed, and are visible even through the skin in living specimens of certain species of Kaloula.Ninety‐one genera and 553 species of the frogs and toads of the world were examined for the presence or absence of this structure. It is distinct in the common American and European ranids, such as Rana pipiens and Rana esculenta. It is entirely absent in many genera. When present it is found only in adult males, being absent in sexually immature males and females of all ages. Examination revealed no seasonal variations in males of Rana pipiens. This indicates that there is some correlation between the expression of this character and the sexual hormones. No function is assigned to the Linea masculina, although it is suggested that it may be associated in some way with voice production. A discussion of the taxonomic distribution of the character is included.
Spermioteleosis of Bruchus quadrimaculatus, Fabr.
Authors: Mickey George H. 
Published: February 2005

AbstractThe cytoplasmic structures in the spermioteleosis of Bruchus quadrimaculatus were studied, using various fixatives and stains including vital and smear techniques.Mitochondria appear in all stages following spermatogonia, exhibiting characteristic appearances during mitoses and in the spermatids. The [central substance] in the halves of the nebenkern becomes localized along the edges of the outgrowing [ribbons] as the source of the marginal filament. The undulating membrane apparently is formed by the fusion of these [ribbons.] The axial filament arises from the distal centriole, being permanently attached thereto, and lies along one edge of the undulating membrane of the tail.Golgi bodies are first observed in the secondary spermatocyte; they behave characteristically during spermiogenesis, producing the acrosome and leaving a residuum, the Golgi remnant, to be sloughed off with the cytoplasm from the tail.Chromatoid bodies occur in some spermatids but not in others. They migrate backward along the axial filament to be rejected with the Golgi remnant.
Color changes in Palaemonetes
Authors: Brown F. A. 
Published: February 2005

AbstractThe pigmentary system of Palaemonetes vulgaris contains four pigments. These are red, yellow, blue, and white. With the exception of the blue all are found exclusively within chromatophores and are capable of becoming either dispersed into chromatophore branches or concentrated into chromatophore centers. The state of dispersion or concentration of each pigment is quite independent of the state of any other pigment and is determined by the color of the background upon which the animal lies. It is by the mixing of appropriately colored pigments by dispersion of those pigments that the animal adapts itself to its background. The blue pigment appears to be in the same chromatophore with the red but its dispersal is not restricted by the confines of the pigment cells, and its disappearance from tissues seems to be a case of destruction in situ. The rates of measured in background changes. In the case of each pigment, concentration was more rapid than dispersion and the rates for the red and white pigments were approximately the same.
A comparative study of the branchial epithelium in fishes, with special reference to extrarenal excretion
Authors: Bevelander Gerrit 
Published: February 2005

AbstractA study of the brinchial epithelium in representative specimens of Cyclostomata Elasmobranchii and Teleostei fishes has been made, with special reference to the following: 1) the importance of physiological role of osmotic regulation effected by the gills; 2) the presence or absence of specialized secretory tissue; 3) progressive evolution of the fishes and the possible phylogenetic difference between them. In regard to these topics we find: 1) There is no indication of any specialization in the branchial epithelium of fishes indicating a special role in extrarenal excretion. 2) In the respiratory epithelium of fishes widely separated phylogenetically or in fishes in living in fresh or salt water, the only significant differences are that in general the teleosts have a squamous type of epithelium, whereas, the elasmobranchs have in general a thicker polyhedral investment. 3) Mucous cells appear large and numerous on the filament proper, smaller and less numerous in the interlamellar spaces, and on the free surface of the lamellae. These are the only specialized secretory cells which occur in the gills.
Behavior and morphological changes in the leech, Placobdella parasitica, during hypodermic insemination
Authors: Myers Raymond J 
Published: February 2005

AbstractThree to 5 minutes after implantation of a spermatophore in Placobdella parasitica there is a pronounced granulation of the tissues in the immediate region of the capsule. During the following 20 minutes a path 81 to 120 μ across communicating with the sinuses of the body cavity is established. By a mechanical shrinkage of the distended spermatophore the spermatozoa are injected through this path into the coelomic sinuses. They are dispersed through the body by the haemolymph and possibly by muscular contractions of the recipient. Fifty to 75 hours after their introduction into the body some of them arrive in the ventral sinus. From here they penetrate the walls of the ovisacs and take up a position in the lumina in preparation for fertilization. Two to 30 hours after implantation a plug of cells composed of migrating cellular elements of the recipient's body and of cells introduced along with the spermatozoan bundles forms in the subhypodermal region of the sperm path. Twenty to 45 hours later the wound is entirely repaired. Hypodermal epithelium is replaced by a migration into the affected region of similar reserve cells. The parenchymatous tissue is restored by a differentiation and growth of some of the cellular elements making up the plug.
Effects of the flexed‐tailed gene on the development of the house mouse
Authors: Kamenoff Ralph J. 
Published: February 2005

AbstractThe flexures in the flexed‐tailed mouse consist of unilateral fusions of adjacent vertebrae. Fusions, if complete, produce straight stiff segments.In normal mouse embryogeny, the precartilage cells surrounding the developing nucleus pulposus of the embryonic intervertebral disk in the proximal tail region begin to elongate and become fiber‐like at about 14 days after fertilization. In the flexed mouse, such differentiation fails to take place on one side of an affected disk, and these cells develop through cartilage to bone. At such a point there is frequently a bend in the notochordal axis. Other abnormalities of the notochord have been observed. These are not the cause of the flexures.The gene for flexed tail also produces two effects more general in their expression. First, it slows the growth of the vertebral column as indicated by the shorter vertebrae of the proximal tail region. This is observable 13 days after fertilization. Second, it produces an embryonic anemia which is already in existence at 14 days after fertilization. It is postulated that the flexures are due to the retardation of growth at a time which is critical for the intervertebral disks. Whether this retardation is the primary effect of the gene and produces the anemia, or whether the anemia is primary and produces the retardation, the data do not show.
Evolution of the upper jaw mechanism in teleost fishes
Authors: Eaton Theodore H. 
Published: February 2005

AbstractThis study reveals the existence of four distinct but genetically related types of upper jaw mechanisms:1. The non‐protractile, with no mechanism for the protrusion of the pre‐maxillae. The maxillaries form part of the upper margin of the mouth, as in Isospondyli, Apodes and Haplomi.2. The crossed ligaments in the snout as in Acanthopteri, Heterosomata and Anacanthini.3. The twisting action type in which the internal hook of the maxilla drives out the pre‐maxilla as found in Cyprinodontes and Percesoces.4. The rostral or sigmoid ligament attached to the pre‐maxilla as in Cyprinidae and Catostomidae.The three protractile types all possess an enlarged pre‐maxilla with a medium dorsal process, suggesting a common origin of all from a single non‐protractile form of upper jaw.