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  • Inorganic Chemistry  (1,356)
  • Cell & Developmental Biology  (229)
  • 1826
  • 1950-1954
  • 1935-1939  (1,586)
  • 1938  (799)
  • 1937  (787)
Collection
Publisher
Years
  • 1950-1954
  • 1935-1939  (1,586)
Year
  • 1
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Paramecium caudatum becomes much elongated upon centrifuging at 21,000 times gravity. The chromatin is sometimes forced from the achromatic matrix of the macronucleus. The materials in the cell are redistributed according to their relative specific gravities as follows: At the centrifugal end of the cell, crystals, layer of fluid, micronucleus and macronuclear chromatin, food vacuoles and neutral red inclusions, achromatic matrix of the macronucleus, endoplasm with large clear alveoli, and fat, at the centripetal end of the cell. The contracting vacuole is displaced sometimes but not the feeding canals or pore. In some cases the crystals, micronucleus and macronuclear chromatin may be extruded from the cell. Animals which survive centrifuging regain their usual shape and the disturbed materials return to their usual distribution rapidly. Sometimes the crystals remain in large compact masses and are so passed to the daughter cells upon fission. The two components of the macronucleus do not fuse the macronuclear chromatin regenerates an achromatic matrix, and division is somewhat delayed. The old macronuclear matrix persists over a long time and sometimes interferes with division. Animals which have no micronucleus may survive and divide, but no amicronucleate races have been established. Apparently macronuclear chromatin is necessary for the survival and division of P. caudatum; in the absence of the macronuclear chromatin no replacement occurs from the micronucleus. The membrane of the contracting vacuole is temporary.
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  • 2
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    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 60 (1937), S. 317-324 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The last muscle in the transverse superficial throat series in all genera of salamanders is here called ‘gularis.’ This eliminates a long list of synonyms. A description of its metamorphic changes in Dicamptodon (Ambystomidae) and comparison of the larval and adult conditions in this genus with those in other known genera clears up the homologies of the muscle throughout the series. The study is based on dissections and a survey of the literature covering all important groups except the Hynobiidae.
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  • 3
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 60 (1937), S. 379-391 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The skull, mandible, atlas, scapula and the six long bones from seventy-four male and sixty-nine female skunk skeletons were weighed. Nine dimensions of the skull, two dimensions of the mandible and of the scapula, the length of the os coxa and the lengths of the same six long bones, were measured from 99 male and 109 female skeletons.The weights of the skull and of the nine bones are significantly heavier in the male skunks and all but one of the linear measurements are likewise significantly greater in the males. The weights and the linear dimensions of the skull and the mandible are more variable in the males but the lengths of the long bones are more variable in the females.The rather high positive correlations of the skull weight and the weights of the other parts of the skeleton studied, show that the weight of the skull is a good criterion of the weights of the other bones. These correlations are slightly higher in the males. The nineteen linear dimensions are likewise well correlated with the skull length. They average somewhat higher in the females.The data on the symmetry of the paired bones are not very conclusive, but there is a preponderance of heavier and longer right bones and a crossed symmetry is suggested.
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  • 4
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 60 (1937), S. 407-443 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Mexican scorpion Centruroides shows exactly the same type of chondriokinesis (by ring formation) as that hitherto known only in the related form Centrurus, as earlier reported by one of us ('31). The Golgi bodies show no trace of ring formation but are distributed by random assortment like that of the chondriosomes in other scorpions. The Golgi bodies, clearly visible in vivo, show the typical plate-like or lamellar structure characteristic of them in other forms. In the first division, after Weigl, there appear to be two metaphase stages, an earlier one in which the dictyosomes are irregularly scattered and a later one in which they tend to mass near the mitotic poles. In the same division, after Champy-Kull, the (presumable) dictyosomes are regularly massed near the poles and may be traced through the whole mitosis. The neural red bodies (‘vacuome’) undergo an irregular distribution and are cast out in the slough. The problem of distribution and localization in the sperm-cell formation are discussed with reference to the principle of genetic continuity in the germ cell.
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  • 5
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Accounts of cortical adrenal development in urodeles are few in number and mostly incomplete from the point of view of development. Hence, an investigation was initiated to fill in existing gaps and present a complete developmental history of the glands in one of the urodeles.The primary anlagen of the cortical adrenal (interrenal) were seen first in the 8.8-mm. embryo as paired or unpaired cell groups in the interrenal area of the 'tween zone lying either in contact with or just beneath the coelomic epithelium. It was not possible to determine definitely whether they originate from the coelomic mesothelium or from the subjacent mesenchyme. Subsequent primordia are formed continuously throughout the period of larval development in an antero-posterior time sequence. Almost immediately they become associated with the postcaval system and the relationship thus established persists throughout life. There is no evidence of a budding process as described by Albrand ('08).During development there is a progressive increase in the size and number of cortical masses, an increase in the total area occupied by them, and a posterior shifting of the tissue as a whole as determined by its position in relation to the spinal ganglia. The definitive distribution is attained at the time of metamorphosis. The tissue occurs abundantly along the postcava, but strands along the median edge of the mesonephroi, as in some urodeles, are only sparingly developed.
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  • 6
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 1-26 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Panniculus carnosus is well developed in the five Didelphids studied. It is described in three parts: pars dorsalis, pars thoracoabdominalis and pars pudenda, in Marmosa, Didelphis, Metachirops, Metachirus and Chironectes, and in Orolestes, a caenolestid marsupial. Pars dorsalis is well developed in all five genera, but not so well developed as in Orolestes; pars thoracoabdominalis is present in all five Didelphids, but not in Orolestes; and the degree of development of pars pudenda is correlated with the development of the pouch, being absent in Orolestes, weak in Marmosa and strong in both males and females of the other genera. In Chironectes, in which genus the male develops a pouch, pars pudenda is strikingly developed. The ‘sphincter marsupii’ of other writers is considered to be a portion of pars pudenda.In early development an epidermal ridge arises surrounding part of the mammary area. In Marmosa these ridges move laterally and posteriorly before the expanding mammary area. In Didelphis, Metachirops, Metachirus and Chironectes the ridges form the lips of the pouch. The pouch is formed when the ridges remain stationary and the expanding mammary area throws the skin into a double-walled fold.
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  • 7
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 127-148 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Gelgi bodies in Meretrix casta being visible in fresh eggs, an attempt was made to elucidate the nature of the contents of neutral red vacuoles. These are neo-formations which arise on treatment with neutral red Ringer. As recent researches have shown that neutral red forms compounds with enzymes, it is suggested that the new vacuoles in Meretrix are visible products of the attempt of the Golgi apparatus to eliminate neutral red which is a foreign substance to the egg. The function of Golgi bodies in the control of cell metabolism by production of intra-cellular enzymes is discussed.
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  • 8
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 175-221 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The reproductive organs of Bruchus quadrimaculatus Fabr., and B. (Callosobruchus) chinensis L., including histology are described in detail. The role of the different parts of the male and female copulatory apparatus is discussed and the physical composition and function of the secretions of the accessory glands are indicated. The specific differences in the structure of the genitalia of the two species are shown.
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  • 9
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using the percentage of mitotic figures in the cells as an index, a study was made of the distribution of cell multiplication in the development of the chick embryo. Counts were made of all regions in embryos ranging from the embryonic shield stage to sixteen somites, and of the neural and sensory epithelia and axial mesoderm of older embryos. Figures are presented which are believed to establish the sufficiency of mitotic division in producing the cell increases in the early embryo. In the developing primitive streak, areas of superior division rate were found in the presumptive medullary plate ectoderm at the sides of the streak. The node and the primitive plate tend to exhibit lower rates than the axis of the streak. The posterior nerve cells multiply more rapidly than the average of the neural tube, and areas of activity in the mesoderm tend to be located near the posterior end. An antero-posterior gradient of the index is indicated in the anterior neural tube, meeting a transient postero-anterior gradient of the hinder cord in the yolk-sac region. A lower rate of division in the floor than in the sides of the neural ectoderm may be implicated in the inrolling of the medullary plate and in the ventral ourvature of older embryos. All indices drop progressively with advancing age and differentiation.
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  • 10
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 11
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 453-471 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the fifty generations of reared Nemeritis, males have been totally lacking. Oogenesis is atypical in (1) the occurrence of a pronounced and lengthy prochromosome stage, (2) the partial fusion of the eleven tetrads at early first anaphase, (3) following first anaphase, a return of all dyads from both poles to form a common second metaphase plate consisting of twenty-two separate dyads, (4) a second division which forms a single polar nucleus and an egg nucleus, each with twenty-two chromosomes, (5) the parthenogenetic development of the egg nucleus with twenty-two chromosomes. Oviposition, which occurs at first anaphase, is followed by a pronounced swelling of the egg through osmosis. Oogonia, follicle cells, cleavage nuclei and somatic cells in later embryogeny all show twenty-two metaphase chromosomes, while pupai tissue shows also tetraploid and octoploid complexes.
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  • 12
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 525-561 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Descriptions and figures of the subordinate sex-organs are given for thirty species taken at random throughout the entire family.It is found: that the higher genera have organs not present in the lower; that they have a storage sac for mineral particles to be added to the secreted capsules within which the eggs will develop; that the anus is more or less fused to the mouth of the oviduct to allow of easy passage of the above materials from anus to oviduct; that spermatophores grade from simple elongated tubes of the lower to stout double tubes with various forms, with spicules, or with spirals, in the higher forms; that the sacs for holding the spermatophores may be simple, when the spermatophores are cast out after discharge, but are more evolved when spermatophores are to be permanently retained and digested; that while lower forms have no sex organs upon the head, peculiar organs occur in the higher genera, in one or both sexes.These organs have value as aids in classification of genera within the family Neritidae. The very marked coordination among these organs may be better understood when further observation reveals how they are used in sperm transfer.
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  • 13
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 61 (1937), S. 581-611 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Anatomically, the structure of the pancreas in four species of anura studied, is very similar during various stages of development. The gland is greatly reduced in size during both artificially induced and natural metamorphosis. When metamorphosis is artificially induced, the regression of the pancreas occurs somewhat earlier and is a little more rapid than in the case of natural metamorphosis, but the condition exhibited at the end of the phenomenon is similar in each case. Correlated with the anatomical regression during metamorphosis, many of the acinous cells, small collecting ducts and sinusoidal capillaries, undergo degeneration. This histolysis occurs somewhat earlier in animals that undergo artificially induced metamorphosis, but regeneration occurs about the same time in both metamorphic types. Most of the degenerated elements are autolyzed in situ; some are sloughed into sinusoidal capillaries; while a small number are eliminated through pancreatic ducts. It is doubtful whether these elements are ingested by phagocytes. The pancreas, in certain cases during later stages of metamorphosis, appears to take on a temporary hematopoietic function leading to the differentiation of red blood cells. Zymogen granules, lipoid granules, and X-granules are demonstrated in the anuran pancreas. X-granules, found in the larvae, are indeterminate in nature and are quite probably remnants of vitelline material found in the early embryo.
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  • 14
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    New York, NY : Wiley-Blackwell
    Journal of Morphology 62 (1938), S. 91-111 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The clam Mya differs from other pelecypods which have been investigated in this respect in having most of the reserve nutritive materials formed within the vacuolated follicle cells of the gonads instead of within the very limited amount of mesenchymatous connective tissue of the visceral mass. The profusely branching tubular gonads originate from two groups of primordial germ cells situated in the position of the future genital apertures. The germinal primordia soon become differentiated into two types of nuclei, one of which becomes associated with the large, vacuolated follicle cells, which form the principal volume of the gonadal tissue, while the other type proliferates to form the primary gonia which become widely scattered along the walls of each alveolus.There is much degeneration and cytolysis during gametogenesis in both sexes, with the accumulation of characteristic inclusions within the follicle cells. Atypical spermatogenesis followed by cytolysis occurs throughout the year but the normal method only in preparation for spawning. No evidence of protandry or change of sex was obtained; only three hermaphrodites were found in the examination of more than 1000 individuals.
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  • 15
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    Journal of Morphology 60 (1937), S. 361-377 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The adrenal-autonomic systems were studied in embryonic and juvenile alligators. In the class Reptilia virtually no previous work has been done on the adrenal-autonomic systems.The adrenals are definite bodies, distinct from the kidney. In young forms they are in close proximity to the gonads and in both the embryonic and young forms the adrenals lie against the wall of the inferior vena cava.Cortical cells predominate. In embryonic forms the medullary tissue is not dispersed as in older forms. The medullary tissue lies in close proximity to the blood sinuses or may completely surround them.The arterial supply is scanty there being only a few small arteries to the adrenal while the blood supply from the inferior vena cava is profuse.The innervation is segmental in nature with four or five consecutive sympathetic ganglia giving off sympathetic nerves to the adrenal. Parasympathetic innervation was not observed in the forms studied. The innervation suggests a transition from lower forms with their segmental diffuse medullary material to the higher forms that display concentration of nerve supply and adrenal tissue.
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  • 16
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    Journal of Morphology 60 (1937), S. 325-359 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Comparative data give the basis for reinterpreting alleged chromidia, mitochondria and Golgi material described for certain rhizopods.Three distinct groups of granules can be demonstrated in both Amoeba and Arcella by techniques ordinarily employed for revealing chromatin elements of a cell, mitochondria or Golgi material. With respect to physico-chemical properties the granules appear identical with certain forms of bacteria in the culture media. They are not destroyed by alcohol, ether, or Altmann's fluid containing 5% acetic acid.These granules are apparently bacteria; two groups representing permanent cytoplasmic entities either as symbionts or commensals, the third possibly temporary invaders.None of the cytoplasmic inclusions of these rhizopods have given the characteristic mitochondrial reaction when treated with Janus green. Spherules and granules, or alleged Golgi material, in Amoeba blackened with osmic acid can be revealed by techniques ordinarily employed for demonstrating the chromatin elements of a cell. Similar spherules and granules occur in the gelatinous material of the culture media, free or in bodies similar to those sometimes found in food vacuoles.In Arcella, neutral-red-stainable and osmiophilic bodies, apparently identical with granules or small globules found individually distributed in the cytoplasm, can be observed both in food bodies in food vacuoles and in similar food organisms in the medium. Those occurring in the cytoplasm may represent indigestible material.
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  • 17
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    Journal of Morphology 60 (1937), S. 445-458 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A description is given of the gross anatomy of the tracheal system of the larva of Drosophila melanogaster. Comparisons of findings are made with those of Lowne for Calliphora, Wahl for Eristalis, Simms for Hylemyia, Dufour for Sarcophaga, Wandolleck for Platycephala, Trägårdh for Ephydra, and De Meijere for Lonchoptera.
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  • 18
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    Journal of Morphology 60 (1937), S. 489-519 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Plethodon cinereus is favorable for a study of the history of the germ line. The germ cells are large, while the gonads are small and show an almost diagrammatic structure. Germ cell degeneration is not extensive during ontogeny. As long as all the germ cells contain yolk during development, these cells are derived solely from germ cells. In Plethodon, yolk lasts in all germ celis through sex differentiation. A comparison of the number of mitoses necessary for the primordial germ cells to produce the numbers of germ cells in gonads where every germ cell contains yolk, with the mitoses necessary for the primordial cells to produce the adult complements of germ cells, shows that at least 72% of the increase of germ cells can be followed by yolk. A cytological study from the embryo through the adult sexual cycle gave no evidence that somiatic cells ever transform into germ cells. Mitoses are abundant in the testes of salamanders starved 4 months. This fact together with a statistical study on the adult male sexual cycle indicates that the germ cells present in the testis do not need to be augmented by transformed somatic cells. It is concluded that in Plethodon germ cells alone give rise to germ cells, and that the germ line is continuous.
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  • 19
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A cytological study of the complete life cycle of Nyctotherus cordiformis (Ehr.) Stein, a heterotrichous ciliate from the large intestine of tadpole and adult Hyla versicolor hosts is presented. In division a partial dedifferentiation of parental ingestatory structures occurs, then redifferentiation, to be retained by the anterior daughter. For the posterior daughter, the ingestatory apparatus arises de novo. In conjugation, two ciliates fuse along their peristomes. The macronucles undergoes complete fragmentation while the micronucleus divides three times. The first pregamic division results in two micronuclear products; the second division, four micronuclear products, three of which degenerate. The remaining product enters into the third pregamic division to produce the two functional, migratory and stationary, pronuclei. Interchange of migratory pronuclei follows at the fused anterior ends of the conjugants to form the amphinucleus which divides once to produce the micronucleus and the macronuclear anlage. Development and behavior of the unusual macronuclear anlage (‘spireme-ball’ of Stein and Schneider) is described for the first time. At the end of the conjugation process, ingestatory structures of each conjugant completely dedifferentiate while a complete new set arises de novo posterior to the old ones. In this case, conjugation occurs only in tadpoles which are metamorphosing into frogs. Conjugation here is interpreted as an effort made by the ciliates to overcome a physiological crisis during the drastic host transformation changes.
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  • 20
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The types of processes encountered in the various species investigated are described. There is included the topography and structure before birth of the gonads, mesonephric ducts, urinary sinus and gut. Following birth, there are but slight changes in the topography of these organs. The most important structural change involves a complete ectodermal reconstitution of the end of the gut to form a true rectum. The vascular supply to the processes in the different species is similar and varies only in the minute details. The arterial supply is furnished by an extension of a single mesenteric artery along the gut. The number of arteries and their position at the gut opening depends on the number and position of the processes at that point. Two venous channels drain the processes; one is somatic and drains into the caudal vein, the other is visceral and empties into the hepatic portal through the subintestinal vein. The former drains the posterior process, the latter, the anterior processes. This basic pattern is constant in all species investigated. A description of the rich capillary plexus on the surface of the processes is included. With the resorption of the processes after birth, vessels that supply them become variously modified. The vein to the anterior processes and the single artery are discontinued. The vein that drains the posterior processes either disappears or is retained in part, undergoing secondary connections.
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  • 21
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    Journal of Morphology 61 (1937) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 22
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    Journal of Morphology 61 (1937), S. 223-255 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the spermatogonia of all the genera studied, there are nineteen rod-shaped telomitic chromosomes, which differ considerably regarding their actual sizes in the different genera. However, an analysis of the measurements of second spermatocyte chromosomes shows that as regards proportional sizes and in seriation there is some degree of uniformity within the sub-family. In Aularches, Atractomorpha, Chrotogonus, Colemania and Pyrgomorpha, the members of the smallest pair of autosomes appear as roundish or oval bodies and are comparable in shape, relative size and behavior with the ‘small’ dot-like chromosomes of the general Acrididae, while in Orthacris and Zarytes they are not so and merge into the general series. The sex chromosome is the largest one in the complexes, or the second largest as in Poecilocerus. The usual forms of tetrads occur in the spermatocytes. It is found that the number of ring tetrads in any genus depends upon the length of its chromosomes; in genera with longer chromosomes there are more of them than in genera with shorter ones. While no final explanation has been offered regarding the chromosome relationship between this sub-family and the other Acrididae, some points arising out of the present study have been briefly discussed, and it is shown that a simple process of elimination of two pairs is not sufficient to explain the smaller chromosome number in Pyrgomorphinae.
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  • 23
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    Journal of Morphology 61 (1937), S. 385-397 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Concomitant with the appearance of the early secretion granules the nucleus enlarges slightly, the basichromatin is reduced and discrete acidophilic granules appear within the nuclei. Some nuclei become vacuolated and in others the basichromatin is practically reduced to a thin shell reinforced with occasional chromatic strands. Such nuclei are filled with acidophilic granules.In many instances the portion of the nucleus adjacent to the secretion is greatly modified, the basichromatin is reduced and presents an alveolar pattern with the alveoli filled with acidophilic material and elongated at right angles to the nuclear membrane. This appearance suggests that material is passing from the nucleus into the cytoplasm but no cytological evidence of such a passage was obtained.During the storage phase giant nuclei are present. They appear to be the result of a simple hypertrophy but in a few instances it appeared that multiplication by direct division, followed by coalescence might be a contributory factor to their formation.Following thyroidectomy or hypophysectomy the production of secretion was retarded but no profound regression was observed. After treatment with implants or injections of anterior pituitary a mild stimulation was observed.The evidence for nuclear participation in the formation of secretion is not conclusive but many of the changes which occur strongly suggest such an activity.
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  • 24
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The silver chromate method used by Cajal, Fusari, and others supporters of the ‘network’ theory, fixes the contraction bands and (M) membranes in contracted muscle and the (Z) membranes and borders of the (Q) discs in relaxed fibers. The same structures are preserved by fixation in gold chloride. Kolatchev, and Bouin solutions. Muscle tissue subjected, prior to fixation, to fat extractives: ether, chloroform, etc., and subsequently fixed by these methods has an appearance similar to control preparations. The Cajal-Fusari ‘network’ is therefore considered to result from an impregnation of the membranes and bands; the various types of ‘nets’ described by these observers being due to fixation of fibers in different stages of contraction.The true Golgi substance of striated muscle consists of osmiophilic bodies located in the sarcoplasm in proximity to the nuclei. Cone, saucer, or crescent-shaped osmiophilic bodies occur at the poles, and granules, rods or curved rods of similar staining material along the sides of the nuclei. The disposition of these structures varies from nucleus to nucleus. Heart muscle possesses a relatively larger amount of the substance than does skeletal muscle.
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  • 25
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    Journal of Morphology 61 (1937), S. 495-523 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The embryos of twenty-one species of the family Goodeidae have extensive rectal processes (trophotaeniae) which serve as absorptive organs, by means of which the embryos while they are retained in the ovarian cavity absorb substances dissolved in the ovarian fluid. Embryos of three species have not been available for study. No trophotaeniae are present in one species Ataeniobius toweri. There are three general types of trophotaeniae, rosette, sheathed and unsheathed. The structure of the trophotaeniae is sufficiently constant in each species to be used in species determination.
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  • 26
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    Journal of Morphology 62 (1938), S. 1-2 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 27
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    Notes: The regeneration of muscle in larval Amblystoma punctatum is preceded by an extensive dedifferentiation of the old muscles of the limb stump. The process of muscle dedifferentiation consists in a separation of muscle nuclei, surrounded by a small amount of cytoplasm, from the injured ends of the muscle fibers. The dedifferentiation of the cut muscles of the limb stump progresses proximad as far as the origin of the muscles on the humerus and results in a complete transformation of these muscles into undifferentiated cells which appear to contribute to the formation of the regeneration blastema. Shoulder muscles, which were attached to the humerus, also undergo a partial dedifferentiation when their points of insertion on the humerus are destroyed by the degeneration of the perichondrium. These muscles never dedifferentiate, however, for more than one-fourth their original length. The process of dedifferentiation in the shoulder muscles is similar to that found in the cut muscles of the limb stump.The regeneration of the injured muscles occurs in two ways. The shoulder muscles reconstitute themselves by means of terminal and lateral sarcoplasmic buds formed near the distal regions of the muscle fibers. The muscles of the limb proper, distal to the shoulder, differentiate out of local aggregations of blastema cells. No myoblasts were observed.The regeneration blastema arose chiefly from dedifferentiated cells of muscle, nerve connective tissue sheath, perichondrium and cartilage.
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  • 28
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    Journal of Morphology 62 (1938) 
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  • 29
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    Journal of Morphology 62 (1938), S. 177-218 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The original innominate bone consisted of ischiopubis only. From this developed a dorsally-directed ilium, upon which the dorsal limb muscles, originally arising from fascia, settled, and which thrust dorsalward between roots of the limb plexus, thus dividing the nerves into prozonal (dorsal and ventral) and metazonal (dorsal and ventral) groups. The primitive muscles of the tetrapod hip and thigh comprised a dorsal mass, soon divisible into sheets, innervated by both prozonal and metazonal dorsal nerves, and a similar ventral mass comparably innervated. The original two elements thus became four basic elements, and probably in early mammals or mammal-like reptiles all dually innervated muscles split into singly innervated units. With this four-group basis as the chief criterion, but considering other factors as well, it is possible to homologize the muscles of urodeles (ventral components only), lacertilians, mammals, and birds in entirely satisfactory manner, except for doubt in several instances in which specialization has secondarily obscured the precise relationships. In different mammals there is shown a tendency toward a final fusion of certain unrelated muscle units (biceps plus gluteus longus, human type of biceps, adductor magnus, and tensor fasciae femoris with gluteus maximus).
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  • 30
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    Journal of Morphology 62 (1938) 
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  • 31
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    Journal of Morphology 62 (1938), S. 415-443 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the blastula stage the roof of the subgerminal cavity is composed of an irregular layer of cells, the nuclei of which lie in the upper or middle part of the cytoplasm.On the floor of the subgerminal cavity groups of already degenerating cells occur. They represent the vegetative pole of the blastula. Almost every cell contains glycogen, and mitotic cells show no special orientation.In the gastrula stage the cells of the area pellucida become regularly arranged as a single-layered, cylindrical epithelium with basally situated nuclei.The yolk endoderm cells are formed from the proliferating upper layer of the area opaca.The embryonic endoderm is formed at the posterior end of the area pellucida by outgrowth of single cells from a circumscribed area, the primitive plate.This plate eventually bends inward to form a typical archenteric canal, through which endoderm continues to invaginate from the epiblast.The endoderm spreads in a cranial and lateral direction until it has formed a complete layer.The epiblast cells lose their glycogen as they invaginate to form endoderm, which is free of glycogen.In the area opaca the upper layer and the yolk endoderm contain glycogen.The mitotic cells of the epiblast of the area pellucida are always orientated horizontally, but in the primitive plate and archenteric canal they are orientated vertically as well.
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  • 32
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    Journal of Morphology 62 (1938), S. 559-597 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The larval, metamorphosing and definitive aortic arches of Desmognathus fuscus, Plethodon cinereus, Eurycea bislineata, and Gyrinophilus porphyriticus, described in this paper, were investigated because it was thought possible that, if the fourth or pulmonary arch failed to develop in these lungless forms, a new factor associated with the loss of lungs might be revealed.The salient points of structure disclosed, so far as the problem involved is concerned, are: D. fuscus and P. cinereus develop fourth arches which remain functional in the larvae and adults and supply the pharynx, oesophagus, stomach and skin of the shoulder region. In some instances the fourth arch in the larvae of P. cinereus is reduced in length or entirely lacking in which cases correspondingly less of the fourth arch and more of the third arch is present in the adult. E. bislineata and undoubtedly G. porphyriticus fail to develop fourth arches and hence do not possess these in either the larval or adult states.It is concluded, therefore, that the failure of the fourth arch to develop has evidently not been a factor involved in the advent of lunglessness in plethodontid salamanders. Also, the fact that E. bislineata never develops a fourth arch, yet is able to transform, furnishes additional evidence against Figge's view that Necturus fails to metamorphose because the ventral portion of the fourth arch is absent.
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  • 33
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    Journal of Morphology 63 (1938) 
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  • 34
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    Journal of Morphology 63 (1938), S. 75-86 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study is based on serial sections of the occipital and otic regions of a therocephalian from the Tapinocephalus zone. The occipital region as preserved consists of the basioccipitals and exoccipitals. The basioccipital is long and slender and is separated from the more anterior basisphenoid by an unossified zone. The exoccipitals are large and contain a part of the jugular foramen and two foramina for cranial nerve XII.The otic bones are fused together to form a periotic. The most striking feature of the inner ear is the medioventral position of the vestibule. Passing back into the periotic from the vestibule is a deep recessus scala tympani. This recess opens anteriorly into a ventral fenestra in the vestibule, the fenestra rotunda. These structures are similar to those of Dimetrodon and the gorgonopsian.The anterior part of the periotic is projected ventrally to form a basicranial process. This probably arose by intramembranous ossification. The unossified zone between the basioccipital and basisphenoid may represent a persistent basicranial fenestra.
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  • 35
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    Journal of Morphology 63 (1938), S. 63-73 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: A study has been made of the growth of the eye anlage, and of the increase in number of the elements of the dioptric system of larvae of Drosophila melanogaster.In newly hatched larvae the eye rudiment grows fast, but slows down later and becomes nearly stationary during the second half of larval life. The increase in number of elements in the eye disc parallels the growth of the whole anlage and reaches a maximum about 70 hours after hatching. The imaginal disc cells increase in number but not in size, in contrast to other larval cells which increase in size but not in number.
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  • 36
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    Journal of Morphology 63 (1938), S. 87-117 
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    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The form of the vertebral column is definitely related to its function as a supporting rod, a base for attachment of body and limb muscles, and a protection of the spinal cord and nerves. Primitively composed of a series of simple undifferentiated blocks, it progressively becomes complicated through development of articular processes giving added strength and greater mobility. Simultaneously, the centrum and the neural arch become adapted to withstand tension and compression stresses which vary with the movements possible in different regions of the column. These movements are partially determined by the plane of the zygapophyses and the nature of the intercentral articulation, together with the action of the axial muscles and ligaments.In fish and primitive tetrapods the axial musculature serves as the chief locomotor organ and consists of a series of myomeres extending with little interruption from the head to the tail. In tetrapods the locomotor function is taken over by the limbs and the axial muscles become progressively differentiated into long flexors and extensors of the column and gradually lose their external segmentation.
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  • 37
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    Notes: Adult salamanders of Ambystoma tigrinum show a high degree of sexual dimorphism. The normal growth of the urogenital ducts system in relation to the development of the gonads is traced from the sexually indifferent period preceding metamorphosis to sexual maturity at 1 year. Differentiation and growth of secondary sex characters is correlated with spermatogenesis in the male and with growth of ovocytes in the female.Testicular hormone manifests its initial appearance in male differentiation of the wolffian and urinary collecting ducts following metamorphosis. Growth of ovocytes and oviducts begins before metamorphosis and may be assumed to indicate the initial appearance of the ovarian hormone. Females retain the larval arrangement of wolffian and urinary ducts. The oviducts of the male regress during the period of rapid male differentiation. This suggests the possibility of antagonistic activity of the male hormones in Ambystoma.
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  • 38
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    Journal of Morphology 63 (1938), S. 143-161 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Notes: A batch of fifty newts was subjected to complete food deprivation for a period of 4 months. During the experiment twenty-two individuals died and twenty-eight were killed at intervals. From the end of the second month the erythrocytes began to show in increasingly greater numbers a progressive alteration in the nucleo-cytoplasmic ratio. The nucleus of these atypical erythrocytes gradually enlarged and ultimately occupied the entire cytosome. Meanwhile the nuclear reticulum became extremely fine and closely meshed, eventually appearing practically homogeneous and relatively chromophobic. The end result was complete dissolution. The leukocytes became greatly reduced in number, the eosinophils disappearing completely. The neutrophils and basophils were agranular in the blood smears. The erythrocyte transformations represent late results of a chain of factors: cytoplasmic hypotonicity, nuclear endosmosis, attenuation and fenestration of nuclear membrane. The subcapsular lymphogranulocytopoietic tissue of the liver had almost completely disappeared. The spleen was greatly reduced in size; it was essentially lymphoid in character and erythrocytopoietic activity had ceased practically completely. Complete restoration of normal conditions in blood, liver and spleen was effected by the end of 2 weeks by feeding with earthworms. The regenerating blood showed many naked nuclei of disintegrating atypical erythrocytes, many immature erythrocytes in mitosis, increased number of small lymphocytes (lymphoid hemoblasts), large but variable numbers of microcytes, many giant thrombocytes and normal granulocytes.
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  • 39
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    Notes: Colloidal carbon injected into the coelom of the larval lamprey, Ammocoetes, is taken up directly by the pronephric tubules. Due to the absence of nephrostomes the mesonephric tubules do not function in a similar way. The tubules of neither show any intracellular deposition of carbon. The reticular elements which support both these kidneys exhibit pronounced phagocytic and hemocytopoietic activity. Carbon in either a free or included form reaches all the other organs both as a result of direct invasion or secondary distribution by the vascular system. The liver is the only organ whose vascular endothelium exhibits cytopoietic properties. To the diffuse spleen as a site of blood cell formation thus should be added the reticular tissue of the pronephros and mesonephros and the vascular endothelium of the liver. Playing a minor role in a similar way are the intestinal mucosa exclusive of that in the typhlosole and the spongy tissue dorsal to the neural tube.
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  • 40
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  • 41
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    Journal of Morphology 63 (1938), S. 181-205 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Notes: In an earlier paper (Slifer, '37) experiments were reported which showed that in Melanoplus differentialis eggs the hatching enzyme, which destroys the white cuticle, is secreted by the pleuropodia (appendages of the first abdominal segment of the embryo) during the last few days of incubation. In the present report the development and differentiation of the pleuropodia, together with the cytological changes which occur in them before, during and after they become functional, have been followed. The time at which the secretion granules are discharged from the pleuropodial cells was found to be closely correlated with the time at which the tough, white cuticle begins to disintegrate. The cytological evidence, then, supports the author's earlier conclusion, based upon experimental work, that the pleuropodia secrete the hatching enzyme.
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  • 42
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    Journal of Morphology 63 (1938), S. 207-217 
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    Notes: Comparison of intramembral and trunk/limb proportions in the roadrunner (Geococcyx) and two related genera of cuckoos (Coccyzus and Crotophaga), together with a consideration of their habits of locomotion, lead to the following two generalizations: (1) The incipient cursorial leg of more primitive, arboreal birds, with the metatarsus shorter than the femur, is not an efficient mechanism for bipedal terrestrial locomotion. The direct adaptation to the cursorial habit in terrestrial birds lies in the further elongation of the whole leg, the distal segments undergoing a relatively greater elongation than the femur; the greatest degree of elongation is shown by the most distal segment. (2) When the development of terrestrial, cursorial habits in birds leads to diminished use, or discuse, of the wings as organs of locomotion, the wing skeleton becomes reduced in length; each segment of the wing is reduced, but the degree of reduction is greatest in the more distal segments. It is probable that reduction appears first in the most distal segment and later successively in each segment proceeding proximally therefrom.
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  • 43
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    Journal of Morphology 63 (1938), S. 219-227 
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    Notes: The median cord arises as a hypodermal invagination along the midline from stomodeum to end of tenth abdominal ganglion. It separates from the hypoderm, but does not differentiate into any tissue; apparently it degenerates.
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  • 44
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    Notes: There are 19 chromosomes in diploid cells of male Paratylotropidia brunneri; of these, four are V-shaped multiples. There are twenty chromosomes in diploid cells of females; of these, four are V-shaped multiples. If the two arms of each multiple are counted as separate chromosomes, we have the usual number of chromosomes for the Acrididae, i.e., twenty-three in male and twenty-four in female.There are nine chromosomes in the first spermatocyte divisions: seven tetrads, one octad and a decad. The latter is made up of the accessory chromosome associated with an octad.One of the V-shaped multiples in the male is limited to that sex. The homologue of one of the dyads of which it is composed is a free dyad, the homologue of the other forms a V-shaped multiple with the accessory chromosome. The V-shaped multiple limited to the male shows differential heteropycosis in the prophases of the first spermatocyte. There is evidence that its homologous parts are isolated from each other as far as crossingover is concerned.A study of the first maturation division of the heterogametic sex is essential for the identification of the sex chromosome.
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  • 45
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    Journal of Morphology 63 (1938), S. 229-261 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Although thoracic diverticula of the aorta ending dorsally in pulsatile organs were discovered by Brocher as early as 1917 no detailed account of their structure was published. The condition of these structures in the adult was not investigated and their development through larval instars was not followed. Brocher's later papers announced the discovery of similar organs in the orders Orthoptera, Coleoptera and Lepidoptera. In 1931 E. Meyer described in some detail pulsatile organs in the Ephemerida. In general these accounts are either superficial or of doubtful interpretation.The present paper deals with the Odonata and stresses the Anisoptera. Anax junius has been studied as the type both anatomically and histologically in all stages of larva and imago except the first four instars. Other types have been compared with Anax, and some of the other orders mentioned have been checked for presence and nature of these organs.Aortic diverticula and pulsatile organs occur in all Odonata both larval and adult. These are derived from the same origins and their histology is that of the membranes involved in aortic and body walls. Through inference from morphology and from physiological examination it appears that pulsatile organs (1) supplement heart action, perhaps substituting for it during emergence. (2) assist in the functioning of the ostia and ostial glands, and (3) may even be important in production and distribution of hormones.
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  • 46
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    Notes: The germinal epithelium was studied in an effort to determine its role in postpubertal ovogenesis. Active and inactive areas of epithelium were observed regardless of the oestrous periods. The active areas, exemplified by numerous mitoses and a frequent stratification of the epithelium, are foci for egg cell production.Egg cells are produced from the germinal epithelium by: activation, migration and transformation of single germinal epithelial cells; migration and differentiation of nests of cells; ingrowths of cords of cells.Young ova in the cortex of the ovary are at first surrounded by a single layer of flattened follicular cells of germinal epithelial origin. In the subsequent development of the follicle stratified layers make their appearance. The zona pellucida appears as a well-defined structure coincident with the stratification of the follicular layers.The follicular cavity develops as a split between the follicular cells at one side of the follicle. In the mature follicle the cavity is broad and contains liquor folliculi. The theca interna and externa are not distinguishable until the follicle is highly cellular.
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  • 47
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    Notes: The spermatogenetic cycle of the testis of the musk turtle is limited to the summer months of the year, and closely parallels that of the anuran Amphibia. Spermatozoa are present in the testis from September to May, and breeding may occur in either fall or spring. A pronounced increase in the size of the epididymis and a corresponding decrease in the size of the testis occurs at the end of the cycle (September).During the months of March, April and May, all spermatozoa are eliminated from the seminal tubules, and the germinal epithelium is built up in preparation for spermatogenesis. Spermatogonial divisions occur in small numbers in May, and the division tempo increases during June. Primary spermatocytes and maturation divisions appear after the middle of June, and continue through July and August. Spermiogenesis begins in late July, is in full progress in August, and is practically completed by October. Laboratory specimens usually show an active spermatogenesis in winter, but it is not probable that a second spermatogenetic cycle occurs in specimens under normal hibernating conditions.No seasonal changes are observed in the interstitial cells of the testis, and no seasonally variable secondary sex characters are known for turtles. Special studies of the problem are being conducted.
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  • 48
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    Journal of Morphology 63 (1938), S. 345-361 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This species represents a typical example of protandric consecutive sexuality, the male phase becoming functional at a very early age, when the body has reached a length of only 3 to 7 mm. Those males which become functional earliest usually seek the association of older individuals in the female phase; others, maturing later, are more likely to remain solitary. Mated males have accentuated masculine characteristics and retain the male phase longer than solitary individuals or those that are isolated experimentally. Unfavorable environmental conditions postpone or prevent functional sexuality and terminate the male phase promptly without inaugurating the female phase. The influence of the female in accentuating the sexuality of the male is thought to be due to stimuli received by the latter through sense organs in tentacles and penis and mediated by the nervous system through hormonal secretions. Termination of the male phase and transition to the functional female are comparable to metamorphosis from the immature to the mature condition in other animals and, like metamorphosis, the primary (male) sexual phase can be abbreviated or prolonged experimentally, but the sequence cannot be reversed.
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  • 49
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    Notes: Data concerning the seasonal distribution of twenty-two species of nudibranchs are recorded for a period of 9 months. The occurrence of copulation and of egg laying for these animals in the laboratory aquaria is recorded for the same period. These data indicate that the seasonal distribution of certain species is well marked, and that there is in many cases a definite breeding season.The characteristics of the egg ribbons of these nudibranchs are described, and figured by means of photographs. These egg ribbons approach the mathematical form of a spiral of Archimedes. In every case observed, the ribbon was deposited in a counter-clockwise direction, viewed dorsally.The relationship between these observations and earlier work on the life histories of the nudibranchs is discussed.
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    Notes: Salivary gland nuclei in Chironomus regularly show large, conspicuous nucleoli. In Sciara no true nucleoli have been found, but sometimes certain particular chromosome regions expand greatly, forming ‘puffs’ or ‘bulbs,’ somewhat nucleolus-like in nature. Detailed study has been made of the chromosome structure in the affected regions in both genera.In the nucleolar regions of Chironomus the banded structure of the chromosome is distinctly modified. In the case of the large nucleolus the chromosome breaks up into a heavy network in which solid discs are replaced by interconnected chromatic spheres and granules, extending out somewhat into the clear nucleolar substance. In the case of the smaller nucleolus, Balbiani's ring, the banded structure is less disturbed. A chromatic network, resembling a system of rootlets, runs out from the chromatic bands into the clear nucleolar substance.In Sciara ocellaris the ‘puff’ regions are at times normally banded, but at other times in the condition described as ‘puffed.’ The same is true of the ‘bulb’ regions. The relation between nucleoli, puffs and bulbs is discussed. Also that between ‘heterochromatin’ and ‘euchromatin.’ Evidence seems to indicate that the latter are merely extremes in a continuous range involving different relative amounts of chromatic and achromatic materials. The ‘puff’ regions appear to be structurally similar to the chromocenter in Drosophila.
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  • 51
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    Journal of Morphology 63 (1938) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 52
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    Journal of Morphology 63 (1938), S. 397-419 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The summary of this paper is as follows:1From an examination of 108 ovaries from eighty-nine individuals it was apparent that, in the cat a certain but variable amount of degeneration of primary follicles occurs in all life epochs.2The primary oocytes undergo the degeneration, while the follicle cells remain for an undetermined time.3The most profound instances of such degeneration were encountered in kittens of 6 to 9 weeks, accompanying or follwing the resolution of the egg cords into primary follicles and the establishment of the cortical or marginal zone. A sporadic degeneration of young oocytes occurs at earlier periods.4No evidence was seen of a new formation of egg cells from the residual follicle cells after the degeneration of the oocytes. The degenerations of the 6 to 9 weeks epoch are not believed to be of universal occurrence.5No adequate evidence was encountered of a new formation of egg cells from the surface epithelium, either before or after sexual maturity.6No evidence linking the degeneration of primary follicles with the estrous cycle was seen.7The stock of primary follicles established in the first few weeks after birth is believed to be adequate for the growth of graafian.
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  • 53
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    Journal of Morphology 63 (1938), S. 421-439 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The maturation of the germ cells of the two hermaphroditic species, Curtisia foremanii (Girard) and Bdelloura candida (Girard) has supplied the material for this chromosome study.Both species of flatworms are believed by the author to possess a diploid number of twelve chromosomes and a haploid number of six, although Curtisia foremanii has previously been reported as having a smaller and variable number of chromosomes.A tendency of the chromatids comprising individual chromosomes to separate from one another at certain times was noted in both species. This action results in giving the appearance of a larger number of chromosomes than the germ cells actually possess. A further source of apparent increase in chromosome number in the Curtisia oocytes, after treatment with the usual Allen's B3 and B15 and Heidenhain's iron haematoxylin, is the presence of some deeply staining, non-chromatin material.No significant differences in number, form and behavior of chromosomes of male and female complexes were noted, with the possible exception of the tendency of the chromatids to separate from one another, to be greater in the female than in male germ cells.
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  • 54
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    Journal of Morphology 63 (1938), S. 441-475 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Four cases of gynandry in American spiders present the following morphologic deviations: The specimen belonging to Neoantistea agilis (Keyserling) externally is a bilateral gynandromorph with distortion of the single male palp, with half of the epigynum nearly normal; internally both testes and ovaries are present. The Drassodes neglectus (Keyserling) is not a completely developed bilateral gynandromorph. One side has a normal male palp, a larger chelicera and longer legs than the other, the epigynum is complete and normal; internally only degenerate ovaries are present. The Linyphiid, near Bathyphantes, is three-quarters female, the only male organ being an imperfectly developed male palp. Ovaries are well developed but immature, whereas the epigynum is complete. In the Pardosa sternalis (Thorell) the anterior part of the body is male, as indicated by the swollen palps and the length of the legs; the epigynum is completely developed, but internal reproductive organs are missing except for a very much aborted ovary. The bisexuality in all cases has caused degeneration or abnormalities in the reproductive structures.Included is a tabulation of all recorded instances of gynandry in spiders, arranged according to the type of abnormality. The term ‘leg-index’ is introduced to express ratio between length of the leg and length of cephalothorax.
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  • 55
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    Notes: Centrifuging the eggs of Rana pipiens in the early gastrula stage prevents the formation of the hypophysis in some of the tadpoles. The absence of the melanophorotropic hormone normally secreted by the hypophysis seems to be responsible for the contraction of the pigment cells. In addition, there are actually fewer pigment cells present in both the dermal and epidermal layers of the light tadpoles than there are in the controls. The paleness, therefore, of the tadpoles seems to be due to both a contraction of the pigment cells present and to an actual reduction in their number. The failure of the hypophysis to develop was brought about by centrifuging at an earlier stage in development of the embryo than in previous extirpation studies. The effects produced by centrifuging that are responsible for the failure of the hypophysis to develop are unknown. However, it is suggested that interference in some way with the presumptive hypophysis-forming tissue has resulted in an inactivation of its inductive potencies.
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  • 56
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    Journal of Morphology 63 (1938), S. 491-529 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper is based on evidence obtained from sectioned skull of Galesaurus planiceps, Owen. Width-length index of skull is 67.7; height-width index 47.6. Dental formula is: \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm I\; 3\; or\; 4}}}{{{\rm I\; ?}}} $\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm C\; 1}}}{{{\rm C\; 1}}} $\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{{\rm PC\; 7}}}{{{\rm PC\; 9}}} $\end{document}. Length of prevomer is 24.0 mm., that of skull 62.0 mm. Maxilla contains cavity which appears to be equivalen of sinus maxillaris of mammals. Ear structure shows large internal auditory meatus. There is no evidence that horizontal and posterior semicircular canals pass through bone. Fenestra ovalis is large. Parasphenoid, basisphenoid, and basioccipital are fused. Parasphenoid consists of short body and a medial anterior process. Sella turcica lacks floor, probably due to erosion. Detached bone may be sphenethmoid. Dentary contains two canals, probably vascular. Comparisons with related forms lead to following conclusions: (1) Specimen is of young animal. (2) Dental succession of postcanines, distichical replacement of postcanines, long prevomer, short parasphenoid, incomplete osseous incasement of semicircular canals, and other characteristics label Galesaurus as primitive cynodont. (3) Reduction of parasphenoid and development of prevomer support Broom's view that Ictidosaurus is not a cynodont. (4) Prevomer as nasal septum; fusion of parasphenoid, basisphenoid, and basioccipital; large lacrimal, splenial, and articular; and other characteristics indicate that Galesaurus is off line leading to mammals. (5) In certain respects cynodonts are more mammal-like than gorgonopsians.
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  • 57
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    Notes: The development of the cranial musculature of Amblystoma punctatum is described in detail, for both larva and adult. In addition, a brief account of the innervation of each muscle is given. The study of normal development is supplemented by extirpation experiments performed on embryos in early stages of development. These extirpations include the mesodermal head segments, mesoderm of mandibular, hyoid, second branchial, third branchial arches, and somites 1, 2 and 3. The eye muscles are found to develop from the mesodermal head segments in precisely the same manner as in other classes of vertebrates; head segmentation of Amphibia, though less accentuated, is shown to be homologous with that of other classes. The remaining extirpation experiments corroborate, in general, the finding from normal development studies. An attempt is made to summarize in tabular form the prospective fate of the prechordal plate and parachordal mesoderm, the two earliest divisions of the head mesoderm, with regard to their complete muscle derivatives.
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  • 58
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    Journal of Morphology 61 (1937), S. 149-163 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The spermatozoon of Palaemon lamarrei is like a cricket ball having a small hole at the top. The outer leather covering of the ball represents the nucleus and the internal stuffing the cytoplasmic vesicle, in the formation of which almost the whole of the cytoplasm of the spermatid along with its mitochondrial and Golgi material is sacrificed. The hole is very efficiently plugged with a ring-like centrosome, which gives off inward a large number of axial filaments radiating through the vesicle toward the nucleus and outward a long prominent spine ending into a fine point. The acrosome is conspicuous by its absence. It has been suggested that, as in Paratelphusa spinigera, the cytoplasmic vesicle forms the mechanism, which is responsible for the explosion of the sperm at the time of fertilization. It has also been suggested that the bizarre structure of the sperm is closely associated with the necessity of ensuring the safety of this explosive vesicle until the time of fertilization. The chromatoid bodies described by Fasten in the crayfish, Cambarus virilis, must be interpreted as the Golgi masses.
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  • 59
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    Journal of Morphology 61 (1937), S. 51-58 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The method of micro-injection was used in the study of a large number of tubules. The limits of the several parts of the tubule were determined with a high degree of accuracy without sectioning; the error of the measurements was small. Of 137 tubules studied the measurements of forty-nine comprised the entire length from renal corpuscle to collecting duct or ureter.The proximal tubule was found to be about twice as long as the distal. While the longest proximal tubule was nearly six times the length of the shortest, the great majority of tubules fell within a much shorter range. There was little or no correlation between proximal tubule length and weight of the animal.The proximal tubule is larger in diameter than the distal tubule. Calculations indicate that the area of exposed cell surface in the proximal tubule is nearly four times as great as in the distal; however, compared to tubule volume, a relatively greater cell surface is exposed in the distal tubule.
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  • 60
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    Notes: A study is made of the development of ovarian ova in mature rabbit does before and during various stages of pregnancy and after the injection of thyroid and anterior-pituitary-like hormones. No appreciable ovogenesis during sexual maturity was found. Nine types of ovarian follicle are distinguished according to size and degree of development. Full ovum size is reached in pre-antral follicles, and is marked by the formation of a dictyate nucleus and slight reduction in nuclear size. Full follicle size is attained much later. The nature of follicle migration in the course of development is described. Ovum migration within the follicle is found to be a consequence of the nature of the egg's attachments to the follicular epithelium. The least atresia is found in young oocytes (10%), the larger follicles showing about 60% atretic at all stages of the reproductive cycle. The hormone preparations administered affect only the largest follicles and their contained ova.
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  • 61
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    Journal of Morphology 61 (1937), S. 309-319 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The anlage of the swim bladder of the Atlantic salmon arises as a small mass of undifferentiated cells resting dorso-laterally on the posterior wall of the fore-gut. This mound of cells is proliferated from the narrow band of mesoderm which lies between the epithelium and the serosa of the alimentary canal. The concentration thus formed elongates slowly for 11 weeks. At the end of this time an evagination from the lumen of the right side of the oesophagus grows into it. This tube commences to elongate rapidly just previous to the time of hatching, and reaches the posterior end of the body cavity at approximately the time when the young salmon emerge from the gravel. Throughout the fresh water life of the fish this organ is a relatively large thin walled sac, lying dorsal to the body cavity. Microscopic examination reveals layers typical of those of the digestive tract.
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  • 62
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    Journal of Morphology 61 (1937), S. 485-494 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper presents an account of the morphology of the hypophysis and adjacent hypothalamic regions of young adult Amblystoma tigrinum. The description deals primarily with reconstructed models made from blotting paper; transverse and sagittal sections are also considered. A new term, hypophysis, pars subdistalis, is used to describe a discrete portion of the hypophysis embedded in the medial and ventral portion of the pars distalis. The other portions of the hypophysis also are described in detail.
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  • 63
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    Journal of Morphology 61 (1937), S. 563-579 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Topics: Biology , Medicine
    Notes: This paper correlates the various aspects of the author's previous work on embryonic columnar epithelia and deals especially with the mechanical factors that determine the form of an epithelium. The origin of the terminal bars, the various forms the terminal bars assume, and the significance of the terminal bar net in maintaining the epithelial structure are discussed. The paper also gives detailed consideration to the elongation of columnar cells after division. When this change in shape cannot be attributed to crowding from without, it is suggested that a thrusting action of elongating spindle fibers is the internal force responsible. In either case elongation is influenced by the development of the terminal web limiting the free surface. Further observations on this structure, first described by the author in 1935, are presented. The terminal web, which is generally present in columnar epithelia, is a specialized part of fixed cytoplasm, condensed, and lying in the plane of the terminal bars. It disappears in mitosis, but its reappearance as the new cell elongates limits the area of the free end of the cell. Hence, the terminal web plays an important part in determining the form of columnar cells.
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  • 64
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    Journal of Morphology 60 (1937) 
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  • 65
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    Journal of Morphology 60 (1937), S. 393-405 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The epididymis in the male bird consists of the rete testis, ductuli efferentia, and epididymal tubules. The rete testis is lined with cuboidal epithelium not resting on a basement membrane. When distended with sperm the epithelium appears squamous-like. The tubuli efferentia are lined for the most part with pseudostratied ciliated columnar epithelium resting on a basement membrane. The epithelium is thrown into permanent longitudinal ridges. The epididymal tubules are lined with ciliated columnar epithelium resting on a bastment membrane.The three types of genital ducts are intermingled to some extent, but maintain a definite sequence in their connection with one another. The rete testis drains into the tubuli efferentia, and the latter into the epididymal tubules. These drain into the vas deferens.
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  • 66
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    Journal of Morphology 60 (1937), S. 459-487 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of the male sexual cycles of five species of Plethodontid salamanders indicated that annually occurring non-functional regions at the anterior and posterior ends of the testis are associated with the two types of germ cell degeneration: (1) extensive degeneration of secondary spermatogonia in the anterior region; (2) complete degeneration in the posterior region, beginning with the young spermatocytes, of all germ cells except the primary spermatogonia. The improbability of the posterior degenerations being caused by a suggested climatic action is discussed. The presence only in urodeles of a caudo-cephalic polarity of spermatogenesis over the length of the testis and of these degenerations seem more than a coincidence. The abortive spermatogenetic cycle of immature males shows a caudo-cephalic sequence and the stages of degeneration that are identical with the adult. Inanition experiments indicate that the formation of secondary spermatogonia and the ability to form sperm are not synonomous. It is suggested, therefore, that normally more of the testis is activated than can be brought to a successful spermatogenesis. Since spermatogenesis moves caudo-cephalically, the posterior end will be left outside the functional zone, and consequently the cells degenerate. The anterior degenerations and the failure of anterior end of the testis to be involved in spermatogenesis, mark the anterior regulation of the spermatogenetic process. Degenerations can be regarded as the by-product of the regulation of overactivation.
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  • 67
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  • 68
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    Notes: Testicular cells obtained from Manchurians were chiefly employed for the study. In the primary spermatocyte the X-chromosome presents a three-segmented structure similar to that of rats. This was not clear in our previous studies, probably due to some technical failure. Of the three segments, one frequently assumes a shape suggestive of the Y-chromosome to some authors, but this never disjoins in the first maturation division, and accordingly it cannot be regarded as a true Y. The three segments are designated as P, D1 and D2 segment, the latter two are occasionally combined to form a single D segment. The P segment presents such a great modification of shape, that it led some authors to misinterpretation. The identification of the X-chromosome was uncertain in the spermatogonial group of chromosomes, but in every case of good fixation forty-seven distinct chromosomes were found.
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  • 69
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    Journal of Morphology 61 (1937), S. 165-173 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Observations are reported which fully establish the aglomerular nature of the kidney in the following teleostean species: Hippocampus trimaculatus, Hippocampus kuda, Hippocampus hudsonius, Microphis boaja, Batrachus grunniens and Pterophryne histrio. It is possible that we are dealing with an additional aglomerular species (Microphis sp.), but this cannot be determined from the available material. All species were taken in sea water except Microphis boaja and Microphis sp., which were taken in fresh water.
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  • 70
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    Journal of Morphology 61 (1937), S. 285-307 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cytoplasm of Opalinid infusorians contains two principal components; the mitochondria and the vegetative granules of the endoplasm. A third component in the form of Golgi bodies has been previously described. Under the influence of radium radiations the mitochondria are re-orientated so that they assume a transverse polarity to the longitudinal axis of the organism. Later the mitochondria are segregated by the radiations so that they lie apart from the vegetative granules with which they are closely associated in the normal organism.
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  • 71
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    Notes: The development of the gonads of the marsh hawk, Circus hudsonius, Cooper's hawk, Accipiter cooperi, and the red-tailed hawk, Buteo borealis borealis has been investigated. The occurrence and relatively long persistence of the cortex on both testes of the marsh hawk is evidence of bilateral amphisexuality in this form. The embryonic condition of the ovaries is related to the degree of asymmetry in the adult organs. Nearly symmetrical, paired ovaries were found in three species and varying amounts of reduction of the right ovary in all others.The disappearance of the right oviduct in the ontogeny of the female red-tailed hawk and the occurrence of accessory gonad tissue in male embryos of the same species are described and figured. The extent of reduction of the right ovary of eleven species is described, figured and classified. The following species are listed in the above order of classification: Circus hudsonius, Accipiter cooperi, Accipiter velox velox, Accipiter atricapillus atricapillus, Falco sparverius sparverius, Aquila chrysaëtos canadensis, Buteo borealis borealis, Buteo lineatus lineatus, Buteo lagopus sancti-johannis, Cathartes aura septentrionalis, Buteo platypterus platypterus.It is concluded that two ways by which organs may disappear are realized in the right ovary and oviduct of the hawks. (1) by failure of an embryonic inductor in the case of the ovary, and (2) in the right oviduct by secondary atrophy of an originally well-developed embryonic structure.
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    Journal of Morphology 61 (1937), S. 433-451 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The nasal capsule of the chameleon differs greatly from that of other lizards in several respects. Cartilage is extremely persistent, particularly in the roof. The anterior chamber is produced backward to form an accessory posterior chamber. This posterior extension lies lateral to the olfactory chamber, from which it is incompletely divided by a longitudinal fold which may represent the normal concha.The organ of Jacobson is extremely reduced and occupies an abnormal position with relation to other structures. The olfactory nerves and their branches are much reduced, and the olfactory epithelium is poorly developed. The chameleon is at best a microsmatic animal.
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    Journal of Morphology 61 (1937), S. 473-484 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Notes: This work was undertaken in an effort to determine the reason why the hepatic cell mitochondria of some animals show a structural response to adrenalin while others show no such reaction.It was found that those animals whose mitochondria are altered by adrenalin undergo a relatively great increase in the percentage of water in the liver. This acquisition of fluid by the liver is accompanied by a disturbance of the cell-plasma ratio of the blood. Those species whose mitochondria show no reaction to adrenalin have no change of volatile liver water, haematocrit reading, and probably have no change of total blood volume.
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  • 74
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    Journal of Morphology 62 (1938), S. 3-15 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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    Notes: Comparisons have been made of the weights of the suprarenals of 525 mature female dogs in dioestrus, oestrus, pregnancy and lactation. Tables and graphs show that there was a slight increase in the size of the suprarenals during oestrus. There was hypertrophy of both the cortex and the medulla in the oestrous dogs. Only slight increase was shown in the weights of the glands of pregnant animals when the net body weight was considered and no increase when the total body weight was used in the study. There was no hypertrophy of the glands of lactating animals.There was only a slight variation in the seasonal occurrence of oestrus. From 34 to 37% of the total numbers of mature females examined in the seasons were found to be in oestrus. From 13 to 16% of the total numbers were found to be pregnant.
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  • 76
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    Notes: Nucleoli in the germ cells of certain Orthoptera, Hemiptera and the crayfish have been studied. In Ceuthophilus (camel cricket) these bodies are found to be definitely connected with chromatin threads and are believed to be products of chromatin.The large structure in the ova of Nemobius (cricket) is interpreted as a nucleolus because of its very irregular behavior and apparent complete disappearance.It is found that some of the nucleoli of Gelastocoris (toad bug) arise within the chromatin threads.Observations on Cambarus (crayfish) fail to show nucleolar extrusion, a phenomenon which has formerly been reported for this form.The unique behavior and fate of the nucleolar material in Pselliopus (true bug) is described. In this species the nucleolar material is added to and becomes part of the general oxychromatin network of the nucleus.This study fully supports the opinion that nucleoli have a chromatin origin.
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    Notes: A new limb skeleton will form in regenerating limbs of the larval Amblystoma in which the humerus had been completely removed. The cartilage of the new limb skeleton develops out of a blastema in which there are no cells of cartilage origin. This regeneration blastema is a composite structure made up of cells derived from a dedifferentiation of the injured tissues of the limb. The tissues which have been observed as contributing to the regeneration blastema are: muscles, especially the muscles of the shoulder; connective tissue of the sheath of the brachial nerve plexus; muscle connective tissue; and, to a certain extent, subcutaneous connective tissue. The new cartilage of the limb skeleton develops out of this composite blastema by means of a differentiation of cells in the central axis of the blastema.The amount of cartilage regenerated appears to depend on the mass of the blastema. When the blastema does not extend fully into the glenoid cavity of the scapula, the head of the developing humerus is deficient in size and structure. However, a complete limb skeleton is regenerated when the blastema does extend fully into the glenoid cavity.Since the new cartilage of the regenerated limb has no genetic continuity with the old limb skeleton, it would appear that the limb field exerts some kind of histogenetic determining action.
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  • 78
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    Journal of Morphology 62 (1938), S. 263-297 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Artemia salina, a very widely distributed species in North America, Europe and Asia, breeds freely and rapidly under laboratory conditions, living in all salinities from fresh water to almost saturated brine. Its soft exoskeleton permits of easy sectioning.The morphology and embryology of the segmentally arranged excretory glands - the antennal, mandibular and maxillary glands, are described. The antennal gland, consisting of extracellular end sac and intracellular excretory duct, is located in the second antenna and opens to the exterior on the lateroposterior face of the protopodite. It attains its maximum development by the sixth instar, degenerating by the tenth. The vestigial mandibular gland consists only of an end sac surrounding a schizocoele, and a rudimentary duct. The large maxillary gland in the adult consists of an end sac, an excretory duct of three circular coils, and a terminal duct opening to the exterior. The maxillary gland develops from a mass of mesenchyme cells in the maxillary segment of the nauplius, becoming fully differentiated by the sixth instar.The vestigial second maxilla has two bristles. It serves only as a terminus for the maxillary gland. A pair of small ganglia are accepted as internal evidence for the presence of a maxillular segment.The presence of three pair of schizocoeles in three consecutive segments is interpreted as evidence of homology with the Annelid coelome, with the possibility of further homologizing the excretory ducts with the segmental nephridia.
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  • 79
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    Journal of Morphology 62 (1938), S. 503-521 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In early embryonic stages of Passalus there are, in addition to the brain and suboesophageal ganglion, three thoracic and ten abdominal ganglia; one ganglion to each body segment. Before hatching the tenth, ninth and eighth abdominal ganglia coalesce. During the three larval instars the terminal ganglion remains in the sixth abdominal segment and only minor changes occur. By the end of the third day of pupal life the adult form of the nervous system is practically assumed. All abdominal ganglia are fused into a single, solid, elongated ganglionic mass. Connectives have disappeared between meso- and meta-thoracic and between metathoracic and abdominal ganglia; and with exception of the brain, sub-oesophageal and prothoracic ganglia, the entire ventral chain has come to lie in the mesothorax. The peripheral nerves still arise from the ganglia and ganglionic mass in their same relative positions and still supply the same segments in which they were originally located.
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  • 80
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    Journal of Morphology 62 (1938), S. 599-607 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Analysis of measurements of the trunk region of the vertebral column and of the various segments of the wing and leg skeleton in sixty-four specimens (thirty-four males, thirty females) of Fulica americana shows that: The males average about 7% larger (longer) than females in all parts of the skeleton; the difference is uniform throughout the body. The coefficient of variability ranges from about 3.00 (humerus, et al.) to about 5.00 (hind toe). The correlation between lengths of parts is very high between different segments of the wing skeleton, or of the leg; it is somewhat less between homologous segments of the wing and leg; and it is still less between limbs and trunk. This decreasing order of correlation indicates an increasing order of independence of variability. The wing proportions in Fulica are those characteristic of the type of flight called flatterflug. The proportions of the leg are those of a bird moderately adapted for cursorial locomotion; the very long toes characterize a swimming bird.
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  • 81
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Fundulus and goldfish were subjected to varying degrees of temperature from 0° to 60°C. Heat rigor and lethal temperatures (37° to 40°C.) cause mitochondria to vesiculate, fragment, globulate and dissolve. The Golgi apparatus becomes swollen, breaks into small dictyosomes which migrate to the peripheral cytoplasm, and dissolves. Osmicated fat increases in amount. The vacuoles (vacuome) increase in number. Evidence is presented to show that dissolution of mitochondria takes place by three distinct methods; namely, (1) vesiculation, (2) fragmentation, (3) globulation. The mixochondriome hypothesis is proposed. This is based on the idea that the mitochondria differ in their chemical constitution, an idea which is supported by the fact that each kind of mitochondrion shows a characteristic manner of dissolution. It is believed that the semi-lunar vesicles of goldfish liver cells are not of mitochondrial origin, and that they and the Golgi apparatus are concerned in fat formation.
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  • 82
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cyto-centrosomes containing centrioles but lacking asters originate de novo in great number throughout the ooplasm of Habrobracon eggs during the formation of the first maturation metaphase. These cyto-centrosomes apparently arise from accessory nuclei which are formed from granules extruded by the germinal vesicle. The accessory nuclei react negatively to the Feulgen nucleal test.Asters similar to those present in artificially parthenogenetic eggs appear around many of the cyto-centrosomes, thus forming cytasters. These are manifest only after the female pronucleus establishes an association with a cyto-centrosome, which thus becomes the nuclear centrosome.In the parthenogenetic egg the centriole of the nuclear centrosome is continuous from one cell generation to the next, whereas the centrioles of the cyto-centrosomes which are unassociated with nuclear material are not perpetuated and disappear during early cleavage.Concerning the origin of the first cleavage centrioles in fertilized eggs, evidence shows that in some ova it is entirely maternal, that is, from two cyto-centrosomes, one associated with the female pronucleus and occupying one pole of the first mitotic spindle, and the other associated with the male pronucleus and located at the opposite pole; while in other ova it is maternal-paternal; from two centrosomes, one the sperm centrosome which occupies one pole of the first cleavage spindle, and the other a cyto-centrosome associated with the female pronucleus and situated at the opposite pole.
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  • 83
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    Journal of Morphology 62 (1938), S. 243-261 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Collections of Campeloma rufum were made at all seasons of the year from the Salt Fork River at Homer Park, Illinois, for gross anatomical and histological studies. No males nor male reproductive cells were found, all individuals showing definite female structures. The gonad, found on the columellar surface of the digestive gland, shows ovarian cells. A U-shaped tube from the albumen gland to the uterus receives the oviduct near its proximal end. This duct leads into a glandular pocket, the shell gland, which in turn empties into the sac-like uterus. The uterus terminates near the edge of the mantle in a muscular vaginal tube. The previously undescribed kidney, a glandular, pyramidal organ, lies posterior and to the left of the upper end of the mantle cavity. The kidney possesses two orifices opening into the pericardium and ureter respectively. The ureter opens between the vagina and the anus. Intra-uterine young were observed during all seasons of the year varying progressively from small veliger to fully formed young. A later paper on oogenesis, will attempt to substantiate parthenogentic reproduction for C. rufum.
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  • 84
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A detailed study of Wright's polydactylous monster (produced by a semi-dominant lethal gene) indicates that it belongs to a general type found also in rare human cases. The diagnostic characteristics are: clubbed feet and approximately double the usual number of digits, embryonic posture, microphthalmia and enlargement of the diencephalon, and missing tibia and telescoped sternum; all organ systems in the body except the genital and circulatory are grossly abnormal. The defects appear to be produced by an arrest of morphogenesis and an alteration of relative growth rates. It is indicated that a controlling center of digit formation exists on the lateral (postaxial) side of the foot, that skeletal and dermal structures are controlled by it, but that muscles are differentiated according to the area of the limb in which they lie. The gene itself is not atavistic, although its effects in the heterozygote have that appearance.
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  • 85
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    Journal of Morphology 62 (1938), S. 393-413 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The microscopical examination of the first haploid salamander to live through metamorphosis shows that the transformation to a terrestrial vertebrate was normal and practically completed at the time of its death. All the organs and structures that develop shortly before and during metamorphosis and are typical for the adult salamander, e.g., the integument, the pharyngeal derivatives, and various glands of special function, are present.The nuclei in all organs and tissues of the haploid animal are smaller than normal. This is indirect evidence of the uniformly haploid condition of the animal. The majority of the organs are smaller than in the control but contain a larger number of cells. In some glands, the reduced cell size has been completely compensated by the increase in cell number.
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  • 86
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    Journal of Morphology 62 (1938), S. 375-391 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study is made of the pancreatic islands in Rana clamitans, R. catesbiana, R. sylvatica and Hyla versicolor during various stages of development. The islands, which were first seen in the 8-mm. R. clamitans larvae, originate from the endodermal cells of the primitive pancreatic anlagen. Following early larval development in all of the species, new islands differentiate from the cells of the pancreatic ductules. During metamorphosis, much of the acinous tissue degenerates, but the islands persist. They become aggregated and the definitive islands are formed from the primary islands before the mature adult stage is reached.With the azure-eosin technique, two types of island cells were distinguishable before, or at the time of metamorphosis, in all of the anurans studied. They are designated as the red and blue types. The blue cells are considered the primitive or embryonic type, and may transform into the red type; or the red type may originate independently.
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  • 87
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    Journal of Morphology 62 (1938), S. 523-557 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ovaries of bats, Myotis lucifugus lucifugus and M. grisescens, have been studied in all phases, except gestation, of the annual reproductive cycle. Oocytes arise in the germinal epithelium and grow with an orderly differentiation of the storage products of metabolism - chondriosomes, fat drops, and yolk vesicles. The evidence indicates that the zona pellucida is derived from the oocyte. Squamous cells of the primary follicle become cuboidal and then columnar as follicular growth begins (unilaminar secondary stage). The secondary follicle becomes multilaminar and in a very few cases gives rise to a tertiary follicle by antrum formation. Most growing follicles undergo retrogression by one of two methods. Degeneration of type I is common in multilaminar follicles and begins in the granulosa which is almost completely obliterated before the oocyte is affected. Spindles occur in some of these oocytes and fragmentation is common; phagocytes eliminate the contents of the zona. In type II, which is rare and has been found only in unilaminar secondary follicles, the oocyte degenerates, leaving an uninjured granulosa. Medullary cords are common embryonic vestiges in these ovaries; epithelial nodules are less frequent. Interstitial cells are very numerous in newborn bats, arise throughout life from the hypertrophied thecae internae of retrogressing follicles of type I, are phagocytized and, also, undergo hyaline degeneration, are hypertrophied in late pregnancy, and continue so during lactation.
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  • 88
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Separation of the mantle from the visceral mass on the right side in deeply cupped species of oyster provides a shorter channel for egress of water from the right demibranchs. Correlated with this change is reduction in size of the right epibranchial chamber beneath the adductor together with backward displacement of the adductor itself. This water passage, designated the promyal chamber, develops during the first week after attachment of the oyster larva. The greatest displacement of the adductor and the largest promyal chamber occur in O. frons. The mantle border shows three reduplications of which the innermost, the pallial curtain, controls the amount and the place of entrance and egress of water. The importance of pallial curtains and promyal chamber to survival in turbid waters is discussed; oysters with the promyal chamber have invaded the river mouths, the flat oysters without this chamber have remained in the clear waters of high salinity near the sea. The bearing of these factors on the disappearance of fossil oysters is considered. It is proposed to relate to the genus Ostrea all flat, larviparous oysters which lack the promyal chamber and to raise the subgenus Gryphaea to generic rank to include all deeply cupped oviparous oysters with the promyal chamber. Anatomical and histological features of the pallium and branchial chambers are considered in detail.
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  • 89
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    Zeitschrift für anorganische Chemie 230 (1937) 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 90
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    Zeitschrift für anorganische Chemie 230 (1937), S. 223-224 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 91
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    Zeitschrift für anorganische Chemie 230 (1937), S. 253-256 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Folgende Verbindungen wurden rein hergestellt und beschrieben: \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {[{\rm Co}({\rm NH}_3)_6]({\rm ReO}_4)_3 \cdot 1\raise.5ex\hbox{$\scriptstyle 1$}\kern-.1em/ \kern-.15em\lower.25ex\hbox{$\scriptstyle 2$} {\rm H}_2 {\rm O}{\rm.}} \hfill \\ {[{\rm Co}({\rm NH}_3)_5 {\rm H}_2 {\rm O}]({\rm ReO}_4)_3 \cdot 3{\rm H}_2 {\rm O}.} \hfill \\ {[{\rm Co}({\rm NH}_3)_5 {\rm Cl}]({\rm ReO}_4)_2.} \hfill \\ {[{\rm Co}({\rm NH}_3)_5 {\rm NO}_2]({\rm ReO}_4)_2.} \hfill \\ {[{\rm Co}({\rm NH}_3)_4 {\rm C}_2 {\rm O}_4]{\rm ReO}_4.} \hfill \\\end{array} $$\end{document}Das Aquaopentammin-Perrhenat eignet sich gut zu einem sehr empfindlichen mikrochemischen Nachweis des Rheniums.
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  • 92
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    Zeitschrift für anorganische Chemie 230 (1937), S. 308-309 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 93
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    Zeitschrift für anorganische Chemie 231 (1937), S. 238-248 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1. Sowohl Leitfähigkeitsmessungen in gemischten Lösungen von Berylliumchlorid und Kaliumchlorid, wie noch mehr Messungen von Chlorkonzentrationsketten der Form: Hg | HgCl, BeCl2, KCl | 3,5 m-KCl | 3,5 m-KCl, HgCl | Hg zeigten, daß in wäßrigen Lösungen von Berylliumchlorid bei steigender Halogenkonzentration keine wesentliche Komplexbildung stattfindet.
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  • 94
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    Zeitschrift für anorganische Chemie 231 (1937), S. 269-280 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Darstellung von Caesiumsulfid aus den Elementen in der Leere nach E. RENGADE wurde untersucht und durch Verwendung von Quecksilbersulfid an Stelle von Schwefel eine Verbesserung gegenüber dem bekannten Verfahren erzielt.
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  • 95
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    Zeitschrift für anorganische Chemie 231 (1937), S. 285-297 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 96
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    Zeitschrift für anorganische Chemie 231 (1937), S. 313-326 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 97
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    Zeitschrift für anorganische Chemie 231 (1937), S. 365-371 
    ISSN: 0863-1786
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Verbindungen [PtCl2(C6H5NC)2] und [PtCl2(C6H5CN)N2], die je in nur einer Form bekannt sind, haben sehr große Dipolmomente und sind deshalb cis-Verbindungen.
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  • 98
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    Journal of Morphology 62 (1938), S. 141-175 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This paper is based on information derived from a sectioned skull of Cynariops robustus Broom, a prepared skull of Cynariops longiceps Olson, prepared and sectioned specimens of Captorhinus, Dimetrodon and various cynodonts, and the literature dealing with these forms.In the otic region, it is shown that the internal auditory meatus, the fallopian aqueduct and the semicircular canals change but little in the series from Captorhinus to the cynodonts. Certain structures, the fenestra ovalis, which becomes progressively smaller, the vestibule, which lies progressively more ventral to the floor of the brain case, the recessus lagenacochlea, which increases in size, and the prootic, which enlarges, show progressive change. The fenestra rotundum is discussed at length. It is absent in Captorhinus, just back of the fenestra ovalis in the Gorgonopsia and Dimetrodon, and confluent with the foramen jugularis in the Cynodontia.The length and relationships of the parasphenoid in the Gorgonopsia are offered as evidence supporting the theory of the homology of the reptilian parasphenoid and the mammalian vomer.The sphenethmoid complex in Cynariops is divided into two elements, a basal member, the presphenoid, and a dorsal member, identified as the orbitosphenoid but possibly incorporating a portion of ossified mesethmoid as well.The comparative studies point out certain basic trends of evolution in the Synapsida, and indicate the level of evolutionary development of the groups studied.
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  • 99
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    Journal of Morphology 62 (1938), S. 323-349 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the Anablepidae, a family of viviparous Cyprinodont fishes, the mature eggs are fertilized in the ovarian follicles. The embryos are retained in the modified ovarian follicles until birth and are born when about 44 mm. in length. The embryos develop expanded yolk sacs which reach a maximal diameter of about 10. mm. The vitelline veins on the surface of the yolk sac develop rows of bead-like swellings, yolk sac bulbs, which serve to facilitate absorption of materials from the fluid of the follicle cavity. There is an extensive system of follicular villi upon the internal lining of the follicular capsule, the apparent function of which is to increase the vascular surface of the internal lining of the follicular capsule and to facilitate the interchange of materials between the blood of parent and fluid of the follicular cavity. The follicular villi and the yolk sac bulbs develop at the same time. These two adaptations for viviparity are apparently unique in this family of fishes.
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  • 100
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Viviparity in the teleost fishes is most highly developed in the family Embiotocidae. In Cymatogaster aggregatus, a member of this family, the males are sexually mature at birth. Females born in June and July are inseminated soon after birth and carry the spermatozoa in the ovarian cavity until December when eggs are fertilized. Embryos are retained in the ovarian cavity till the following spring when they are born.The cells of the epithelium lining the ovarian cavity develop internal fluid reservoirs which reach their maximal stage in early gestation when there is an extensive sloughing of epithelial cells. The epithelium returns to its original condition in late gestation and later the cells undergo multiplication. The stroma becomes swollen and contains a large amount of fluid during early gestation and shrinks as the embryos become larger. Many of the eggs, failing to reach maturity at the time of fertilization, degenerate. Degeneration also takes place in numerous smaller ovocytes during gestation but some of them survive to grow during the next season.The cyclical changes in the ovarian tissue of Cymatogaster aggregatus are parallel to those which occur in the ovaries of the Goodeidae and the Jenynsiidae, two other families in which viviparity has been highly developed.
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