bluuebunny/crossref_metadata_2025_split huggingface dataset:
The spermatogenesis of lebistes reticulatus
Authors: Vaupel Jean 
Published: February 2005

AbstractThe germ cells of Lebistes are found in cysts; the younger cysts are toward the cortex. Mitochondria and Golgi apparatus are present. During maturation leptotene, bouquet, pachytene, and diakinesis figures are seen. The spermatocyte chromosomes number twenty‐three; an X‐Y pair is probably present, though the evidence is not conclusive. In spermatid formation the centriole divides to form a rodlet and an axial filament; the nucleus segregates into two materials, one of which is extruded; the remainder first contracts to a cup, comes in contact with the rodlet, then again forms a sphere. The mitochondria are arranged along the proximal part of the axial filament; the sphere flattens and elongates; the rodlet sinks into the head substance and is enfolded by it. The Golgi remnant is sloughed off with the residual cytoplasm, which disappears at the same time the Sertoli cells show an increase in size, suggesting their ingestion of the spermatid remnants. The mature sperm form spermatozeugmen, which are stored in the testicular canal; they are transferred to the female by aid of the modified anal fin.
Studies in the origin of yolk. IV. Ogenesis of Periplaneta americana
Authors: Nath Vishwa , Mohan Piare 
Published: February 2005

AbstractTechnique. This work is based not only on the fixed preparations, but also on fresh cover‐slip preparations treated with neutral red or 2 per cent osmic acid for a short time.Golgi elements and fatty yolk. The Golgi elements are hollow vesicular bodies with a distinct osmiophilic rim and a central osmiophobic substance. In the youngest oocyte they form a circumnuclear ring. Gradually the vesicles spread out, grow in size, store up fat in their interior, and give rise to the fatty yolk. On account of their higher refractive index, due to the presence of fat, the Golgi vesicles can be occasionally seen even in the young oocytes without any treatment.Mitochondria. The mitochondrial granules also form a circumnuclear ring and are later distributed uniformly.Albuminous yolk. The albuminous yolk is nucleolar in origin. Early in oogenesis, the nucleous buds off small, homogeneous, and highly chromatic particles in the cytoplasm, which sooner or later disappear. Subsequently, the nucleolus becomes less chromatic and develops vacuolar bodies in its interior, which, becoming vacuolated exactly like the parent nucleolus, migrate into the the cytoplasm. These bodies become more and more chromatic and travel toward the periphery of the egg, where they grow in size. Ultimately they break down into small, homogeneous, and highly chromatic bodies which are the definitive albuminous yolk spheres and which subsequently grow enormously in size.
The effects of the substratum, divalent and monovalent cations on locomotion in Amoeba proteus
Authors: Hopkins Dwight L. 
Published: February 2005

AbstractThe rate of locomotion in Amoeba proteus is dependent upon the nature of the substratum, the nature of the different divalent and monovalent cations present, and the ratio of the amount of the monovalent cations to the amount of calcium or strontium. Calcium is more efficient than strontium in antagonizing potassium. Magnesium and barium do not antagonize potassium. The four monovalent cations studied in antagonizing calcium are efficient in the following order: Na>K>Li>Rb. Calcium and potassium are more effective against antagonistic cations when combined with chlorine than when combined with phosphate.
On the statocyst of the American cephalopod genera
Authors: Ishikawa Masashi 
Published: February 2005

AbstractFrom the structure of statocysts, in the so‐called phylogenetic tree of the Cephalopoda, the genus Scaeurgus is to be placed on the same branch as Polypus.Meleagroteuthis has the same number of processes as Watasenia, Enoploteuthis, Abralia, Illex, and Stigmatoteuthis, which have ten processes, but in this genus the structure of statocysts seems to be tolerably well developed. For this reason, the author places this genus as a branch between Abralia and Illex.Those three genera—Gonatus, Sthenoteuthis, and Onychoteuthis—which have eleven processes in a statocyst are to be placed in the same branch as Berryteuthis, Gonatopsis, Ommastrephes, Eucleoteuthis, Moroteuthis, and Symplectoteuthis, which have the same number of processes; of these, Gonatus, which has the most primitive structure of the statocyst, is to be put in the lowest position on that branch; but Sthenoteuthis, which has the same structure of the organ as Ommastrephes, is to be placed on the twig near Ommastrephes; and, lastly, Onychoteuthis has the same organ as that of Moroteuthis, which fact induces the author to set this genus in the position nearest to Moroteuthis.The statocyst of Lolliguncula corresponds exactly to that of Loligo, which has twelve processes; this condition puts this genus on the same twig as Loligo.
The morphology of the palmar digital triradii and main lines
Authors: Wilder Inez Whipple 
Published: February 2005

AbstractA study is made of the morphological types of the second, third, and fourth interdigital patterns of the human palm and their differential occurrence as a basis for determining the morphological significance of the digital triradii and main lines, which are the final remnants of the pattern boundaries. Certain types of patterns show a large preponderance, with a correspondingly large percentage of a certain morphological value for each digital triradius, although other morphological possibilities than the usual one are discovered in each case. Correlated combinations of rare patterns are presented and their hereditary nature discussed.
The histology of the blood of some bermuda ascidians
Authors: George W. C. 
Published: February 2005

AbstractThe structure of the living blood cells is described and the cells are classified in the following species of ascidians: Phallusia nigra, Ecteinascidia turbinata, Clavelina oblongata, Symplegma viride. Evidence for the genetio relationship of the various types of cells is discussed.
Chromosome studies. V. Diploidy and persistent chromosome relations in partheno‐produced Tettigidae (Apotettix eurycephalus and Paratettix texanus)
Authors: Robertson W. R. B. 
Published: February 2005

AbstractNumber of chromosomes is 13 (♂) and 14 (♀), the same as in biparentally produced relatives. In diploid groups from partheno‐produced individuals homologous chromosomes tend to lie together, as ‘doubles’ or separated but near each other. In biparentally produced individuals they have as marked a tendency to lie in oppósite halves of the plate. Chromosomes of an individual tend to persist in the same position from cell to cell in the partheno‐produced, with homologues side by side arranged about one center; in the biparentally produced, with seven single members arranged about each of two centers. In the partheno‐produced the cells of younger animals, or of the earlier stages of organs in older animals, have a larger proportion of ‘double’ chromosomes or closely associated homologues.These conditions suggest that the partheno‐produced individual arises from an egg with a single pronucleus in which there were seven ‘double’ or diad‐like chromosomes, and the biparentally produced from an egg with two pronuclei, each with seven ‘single’ chromosomes. The paired position of homologues in Diptera may be due to synapsis‐like tendencies in early cleavage, either as ‘hang‐over’ effects from the preceding meioses or a different type of synapsis mechanism in Diptera. Partheno‐produced male tettigids may be accounted for through non‐disjunction among the four parts of the sex tetrad.
The aortic arches and their derivatives in the embryo porcupine (Erethizon dorsatus)
Authors: Struthers Parke H. 
Published: February 2005

AbstractThis ontogenetic study shows the following facts: (1) the presence of a vidian artery homologous with that of reptiles, which serves visceral elements of the jaw; (2) there exists a transitory occipital artery arising from the stapedial which contributes to the vascular supply of the occipital region; (3) the presence of a transitory fifth arch intimately associated with the sixth arch; (4) there is evidence of at least two presegmental branches of the aorta; (5) in the development of the adult pulmonary stem the right artery forms very little of the common vessel; (6) a single cephalobrachial trunk forms the culmination of arch development; (7) arterial development of the head and neck falls into three phases: (a) a temporary arterial pattern designed to carry nutriment to primitive head structures, (b) a plan of arterial distribution adapted to supply the rapidly forming cartilage and muscle of the jaws, and, (c) a readjustment period when the arterial plan is readjusted due to the increased heteronomy of the head.
A study of living sperm cells of certain grasshoppers by means of the ultraviolet microscope
Authors: Lucas Francis F. , Stark Mary B. 
Published: February 2005

AbstractThis paper discusses very briefly the ultraviolet microscope and the developments which have led to a successful technique for optically sectioning living cells; also the ultraviolet photomicrographs of living sperm cells of certain grasshoppers, which show clearly the spinning out of the chromonema from solid blocks of the diatene stage, the pairing of same in the leptotene stage, the development of the tetrads, the final distribution of the chromosomes in the resulting spermatids and their return to a spiral chromonema, each inclosed in its own vesicle. The details of the cytoplasm are equally well brought out.
Some histological effects of ultrasonic waves on cells and tissues of the fish lebistes reticulatus and on the larva of rana sylvatica
Authors: Chambers L. A. , Harvey E. N. 
Published: February 2005

AbstractSome pathological effects of supersonic waves produced by the piezo‐electric oscillator described by Wood and Loomis ('27) are described.Death of fish and frogs was due to haemolysis of erythrocytes within the gill capillaries. Disruption of gill filaments, trauma, and extravasation in the head and gill region and in the peripheral musculature were noted.No effect on the nervous system was apparent histologically.Organisms were not killed in water under hyper‐ or hyponormal pressures. In these cases no cavitation of gases took place.Isolated frog sartorius muscle in Ringer's was not damaged.Bubbles of gas were easily observed within the muscle cells of the tadpoles when such cells were not more violently disturbed. Such bubbles were abundant in the more fluid muscles of four‐ or five‐day tadpoles, less abundant in 15‐ to 35‐mm. Lebistes, and entirely lacking in adult frog sartorius. Protoplasmic viscosity differences probably explain the gradient.The above‐observed intracellular cavitation explains the muscular destruction, the haemolysis, the change in specific gravity of organisms subjected to the wave treatment, and may offer light upon the stimulatory effect of such waves on excitable tissues (compare Harvey, '28).
A demonstration of the vacuome and the golgi apparatus as independent cytoplasmic components in the fresh eggs of teleostean fishes
Authors: Nath Vishwa , Nangia Murli Dhar 
Published: February 2005

AbstractThe most important conclusion of this investigation is that the vacuome and the classical Golgi apparatus are independent cell components in the oocytes of Ophiocephalus and Rita. The same conclusion has been arrived at by Nath in Rana tigrina. The vacuoles, the Golgi elements, and the mitochondria can be seen intra vitam side by side.In Ophiocephalus the vacuoles give rise to albuminous yolk, as has been rightly claimed by Hibbard for Discoglossus and by Hibbard and Parat for Perca and Pygosteus. The Golgi elements give rise to the fatty yolk as in so many other forms of oogenesis described by Nath and others.In Rita the fate of the vacuoles and the Golgi elements is unknown, as the fish suddenly disappeared from the Ravi during the spawning period.
Spermatogenesis in sturnus vulgaris: Refractory period and acceleration in relation to wave length and rate of increase of light ration
Authors: Bissonnette Thomas Hume , Wadlund Arthur Pehr Robert 
Published: February 2005

AbstractBetween December 10th and January 24th, using red, green, and white electric lights at equal intensities of about 1.7 foot‐candles, sixty‐nine males, with females, were subjected nightly to, (a) constant six‐ and six‐and‐one‐quarter‐hour periods of illumination; (b) periods increasing gradually from one‐quarter to six and one‐quarter hours; (c) no added light (controls), in a basement room lighted by day from three large windows. Relative heat intensities reaching the birds were: for white, 1; for green, 2.5; for red, 10.Birds were killed for testis study at 5, 12, 16, 22, and 23 days.Refractory period was shorter, and modification of spermatogenic activity much greater, under a than under b types of treatment, as compared with controls. Effects were also more consistent.Descending order of testis activity induced at all stages was red, white, control, green, under both a and b.Effects on testis activity are not proportional to heat intensity of incident light, but depend on wave length, since green effect is not intermediate between those of white and red, as its heat intensity is. Green inhibited germ‐cell activity even in birds already at normal midwinter minimal condition.Constant six‐hour red‐light treatments, of this intensity, induced flrst appearance of metamorphosing sperms in twenty‐three days in midwinter.Apparatus and mode of light regulation and measurement are described.
Chromosomes of three species of mantidae
Authors: King Robert L. 
Published: February 2005

AbstractThere are twenty‐seven spermatogonial chromosomes in Tenoder'a sinensis, three of which are larger than the others and lag behind in anaphase. These three chromosomes have been traced through the prophases of the first spermatocyte to the metaphase, where they appear as a hexad. In the first spermatocyte division two of the constituent diads of the hexad pass to one pole, the remaining one to the other, thus giving rise to two types of second spermatocytes, one with thirteen and the other with fourteen chromosomes. There are twenty‐eight chromosomes in somatic metaphases of the female; four of these chromosomes are larger than the others. The sex chromosomes of the male are represented by the formula Xa + Y + Xb, that of the female by 2Xa + 2Xb.Similar conditions are reported for Mantis religiosa and Stagmomantis carolina.
Developmental stages of the chondrocranium in some selachians
Authors: Harrison Bruce M. 
Published: February 2005

AbstractSerial sections of seven embryos were examined, in four of which the chondrocrania were reconstructed. Parachordals appear as independent precartilages on each side of the notochord in the otic region. Later chondrification occurs, and they fuse with the notochord. Orbitals and trabeculae appear as independent precartilages; later, as cartilages they fuse with the basal plate and with each other, forming the cranial wall between the orbital cavity and brain. An apparent shifting posteriorly of the bases of the fifth, seventh, and eighth cranial nerves, in respect to the anterior end of the notochord and to the otic vesicles, occurs between the 10‐mm. and the 60‐mm. stages. The otic vesicles, proportionately small in the 10‐mm. stage, reach their relatively largest size in the 19‐mm. embryo. The floors of the otic capsules begin as lateral extensions of the basal plate at the 25‐mm. stage, and from these anlagen chondrifications extend, forming the anterior and posuerior cupolas. Most of the tegmen cranii forms by chondrifications that approach the median plane from each side. It is practically complete in the 60‐mm. embryo. The cervical neural arches also contribute in forming the tegmen cranii and the occipital region. The ventrally recurved end of the notochord of the 10‐mm. stage persists through the 60‐mm. embryo.
The early develoment of the duck's egg, with special reference to the origin of the primitive streak
Authors: Chen Beh Kang 
Published: February 2005

AbstractThis study deals with the development of the duck embryo from the unincubated blastoderm to the 1‐to‐3‐somite stage. In the unincubated stage the thickened posterior germ wall is the most active region mitotically, contributing cells to complete the entodermal layer. The slightly thickened ectoderm of the posterior half of the pellucid area is the precursor of the embryonic shield. During incubation this ectoderm increases in height, forming the embryonic shield. The primitive streak arises in the posterior part of the shield, where tall ectodermal cells in the midline become several‐layered and proliferate cells from their ventral surface which migrate laterally, becoming mesoderm. At first short and broad, the streak becomes longer and narrower until it attains its definitive stage.The greatest proliferation of ectodermal cells occurs always at the anterior end of the streak of all stages, forming at the definitive stage a definite thickening–Hensen's node. Proliferation diminishes posteriorly along the streak.The number and orientation of mitotic figures indicate cell movements as follows: Prestreak stages–ectodermal cells migrate from posterior part of shield toward midline, thence forward in midline; early streak stages–anterior movement in streak and to sides of streak, and lateromedial movement from sides toward middle of streak; definitive streak stages–postero‐anterior and lateromedial migration of cells.The embryonic axis, of prestreak and streak stages, lies approximately at right angles to the egg axis in slightly over 50 per cent of the cases.
The structure of opalinids, as revealed by the technique of micro‐incineration
Authors: Scott Gordon H. , Horning E. S. 
Published: February 2005

AbstractOpalinids from the rectum of Rana pipiens were isolated in large numbers and fixed in a mixture of nine parts of absolute alcohol and one part of neutral formalin. These were embedded in paraffin and incinerated according to the technique of Policard. Examination of the preparations by dark‐field illumination showed that the micro‐incinerated protozoa retained their distinctive morphological and cytological characters, for the mineral ash had the same topographical distribution as the cell inclusions in the control stained preparations.The coarse vegetative granules of the cytoplasm were preserved as distinct masses of ash which corresponded exactly to these bodies in the control preparations. The structure of the myonemata and the cilia was perfectly preserved. The chromatin material of the nucleus, more or less abundant, left little or no ash, which is quite in contrast to the findings of Scott with regard to amphibian and mammalian nuclei.
Polyploidy and metaphase patterns
Authors: Wilson Edmund B. 
Published: February 2005

AbstractA cyst of tetraploid first spermatocyte metaphases is described in the coreid hemipter Archimerus alternatus (Say), all other divisions in the testis being of normal diploid constitution. The striking fact is that in spite of the doubling of their number the chromosomes closely follow the group pattern characteristic of the corresponding normal divisions. In the latter the first metaphase always shows a ring of six autosome bivalents with a single m‐chromosome bivalent at its center and a single univalent X‐chromosome lying outside the ring (as in coreids generally). In corresponding tetraploids the numbers are respectively 12, 2, and 2. Three additional interesting features of the tetraploids are: 1) the fact that the two m‐bivalents are always lined up end to end to form an axial quadrivalent chain; 2) that although two X‐chromosomes are present (as in the normal female), they are never united to form a bivalent as in that sex; and, 3) that in the prophases (of which a few are present in the cyst), at least one pycnotic X, or chromosome nucleolus, is present.A critical discussion is offered of the general problem of the mechanism of chromosome movements and groupings, together with a review of recent literature. The conclusion is urged that the chromosomes themselves play an active and important part in these processes, and the possible genetic relations between chromosomes and spindle substance are discussed.
Embryology and life history of chaetopleura apiculata
Authors: Grave B. H. 
Published: February 2005

AbstractThe breeding season of Chaetopleura apiculata begins about June 20th to June 25th and continues until about October 1st. Spawning takes place in the early evening, 8 to 11 O'clock. The cleavage and early development are strikingly similar to that of Ischnochiton as described by Heath, and is typically molluscan. The egg is enclosed in a bristly chorion from which it hatches after twenty‐five to thirty hours. The larva is a large opaque trochophore which gradually transforms into a veliger larva by the development of the shell and foot. It settles to the bottom and metamorphoses into the adult form after six to ten days. It becomes sexually mature in one year and is full grown in three or four years, when it measures 29 × 18 mm. or less.
Morphogenesis of the brain
Authors: Herrick C. Judson 
Published: February 2005

AbstractThe fundamental structure of the brain stem is uniform throughout the vertebrate series, not essentially because it expresses an architypical pattern, but because of the constancy of peripheral connections and their internal relationships, both of which are parts of an apparatus of adjustment to environment which is common to vertebrates. Other parts of the brain are more variable because, with complication of the behavior pattern in higher forms, more elaborate and diversified mechanisms of correlation and integration are requisite.The brain stem between the olfactory bulb and other primary sensory centers is plastic tissue not dominated by any single sensory‐motor system; it is the meeting place of descending and ascending sensory paths. Here the chief apparatus of correlation and integration is elaborated. From it emerge the complex thalamic and cortical adjustors. The pallium is not a primary constituent of the vertebrate brain. The pallial type of organization gradually emerged from the more ancient subpallial type and comes to mature expression in the cerebral cortex. Several instructive stages in the progressive differentiation of cortical structure and connections are seen in the amphibian forebrain, but the process is not consummated. Amphibia have no cerebral cortex, though cortical primordia are evident here and in various fishes. Static concepts of architypes and the dialectic of ‘form‐analytic’ argumentation are replaced by a more dynamic treatment of morphogenesis.