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  • Life and Medical Sciences  (14)
  • ASTROPHYSICS
  • 1935-1939  (14)
  • 1939  (7)
  • 1936  (5)
  • 1935  (2)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 58 (1935), S. 555-571 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Each contractile vacuole system of Paramecium multimicronucleata is made up of a number of components, some temporary and others permanent. The contracting vacuole with its membrane is a temporary structure as are the vesicles which fuse to form it. The vacuole discharges its contents to the exterior leaving a vestige closing the pore. The pore, with its discharging tubule and the feeding canals are permanent cell organelles. The feeding canals end in injection tubules which extend up to the pore. The vesicles, which later fuse to form the vacuole, are formed at the proximal end of the injection canals, leaving a membrane closing the canal, much as a food vacuole is formed at the gullet. The canal-fed contractile vacuole of Paramecium is very similar to the vesicle-fed vacuole of Euplotes both as to its origin and its fate. The Nassonov homology is rejected.
    Additional Material: 8 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 59 (1936), S. 441-451 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Frog kidney, when fixed in 4 per cent formalin and subsequently treated with Kolatchev solutions, is found to contain osmiophilic bodies which not only appear identical to the Golgi substance of Kolatchev fixed controls but which also resist bleaching in hydrogen peroxide or potassium permanganate solutions. If a formalin fixed kidney is dehydrated and extracted with various fat solvents and subsequently fixed with the Kolatchev technique, Golgi bodies are usually completely removed but occasionally cells are found which contain spherical globules of osmiophilic substance scattered through the cytoplasm.Kidney tissue fixed in a mixture of 95 parts of alcohol plus 5 parts of formalin before application of the Kolatchev solutions does not contain Golgi bodies. The same results are obtained if benzene is used instead of alcohol and formalin. Striated muscle, when treated in a similar manner, contains darkly stained (Z) and (M) membranes, therefore the osmophilic substance present in muscle quite widely daerent, chemically and physically from that contained in kidney cells.It is apparently an established fact that formalin preserves phospholipids in tissues nnd this investigation has shown that Golgi bodies in kidney cells can be demonstrated following fixation in formalin. Moreover, the Golgi bodies, which are preserved by formalin, can be removed by extracting the tissue with fat solvents. This evidence, therefore, strengthens the hypothesis that true Golgi substance is phospholipid in nature.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 59 (1936), S. 313-325 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Parabrotula dentiens is a viviparous deep sea Brotulid fish. The embryos at the 6 mm. stage are held within the ovarian cavity as are the embryos of Zoarces, the Embiotocidae, the Goodeidae, the Jenynsiidae and the Anablepidae in the later stages. The embryos of Parabrotula dentiens are equipped with external processes which are attached around the anus and to the ventral wall of the embryo for a short distance in front of the anus. The processes have a spongy connective tissue stroma and are covered with a syncytial layer. It is assumed that the processes augment the body surface of the embryos and have a nutrition-absorbing and an oxygen-absorbing function.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 64 (1939), S. 37-46 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: 1. The prostomial glands, as described by Bourne, are deep-lying and unicellular, are distinctly different from the salivary glands, and their contents do not stain with boraxcarmine. They are ectodermal in origin.2. The material for the cocoon is secreted by the clitellar glands, while the prostomial glands secrete the yellowish plugs at the two poles which close the two ends of the cocoon.3. A fortnight after the cocoons are formed, the plugs become detached, leaving two outlets one at each pole, for the young leeches to wriggle out of the cocoon.4. The detachable plugs are possible only if not made of the same material as the cocoon.
    Additional Material: 6 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 64 (1939), S. 67-87 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In Didelphis virginiana and Marmosa mexicana the retina is sauropsidan in type and the eye as a whole is markedly adapted for scotopic vision. The superior half of the fundus of Didelphis is occupied by a tapetum lucidum of the retinal type, formed by the enlarged pigment epithelial cells which are devoid of pigment and packed with reflective particles of unknown composition. Such a tapetum is unique among mammals - in all known sub-mammalian retinal tapeta the reflective material is guanin and is occusible in bright light by migratory fuscin. The retinal capillaries in Didelphis extend to the external limiting membrane, apparently in adaptation to the low permeability of the dense tapetum. Only four other mammals are known to have such capillaries and no inclusive explanation seems to hold for all. Didelphis possesses an ‘area centralis of sensitivity’ associated with the tapetum. Both genera have abundant rods and scanty cones, of three types. The oil droplets of the droplet-bearing single cones and the double cones are colorless and the double cone contains only one, not two as reported by O'Day for other marsupials; nor are the members of the double cone ever alike in size and form. Opossum double cones are thus perfectly orthodox; primitive placental mammals should be examined for double cones and oil droplets.
    Additional Material: 3 Ill.
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  • 6
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 65 (1939), S. 297-321 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 6 Ill.
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  • 8
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Residual germ cells larger than primary spermatogonia but similar in other respects are found throughout the testis in the walls of the lobules and in the cysts of developing germ cells. There is no evidence for germ cell migration through the testis. Spermatogonia arise in situ from residual cells.Forty-two chromosomes are found in the spermatogonial cells. Two of these chromosomes are much larger than the others and possibly represent sex chromosomes. The haploid chromosome number as seen in primary spermatocyte cells is twenty-one. A large ovoid chromosome, considered to be a sex chromosome, lags during the formation of the primary spermatocyte spindle. It divides after the division of the other chromosomes into equal chromosomes which pass to opposite poles of the spindle.The evidence for sex chromosomes as presented here is meagre but is consistent with the evidence from chromosome studies in other teleosts. It has been proposed that sex chromosomes are in a nascent condition and hence are differentiated but little from autosomes and also that the members of the sex chromosome pair are morphologically alike.
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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: A cytological study of the hypophyses of more than 100 female bats, collected at fortnightly intervals from October to April, is reported. The bats were decapitated within 24 hours after collection. and then hypophyses fixed in Champy's fluid or Helly's fluid followed by staining by the acid fuchsin-thionin-aurantia method of Kull.The pars distalis, pars intermedia, and pars nervosa lie adjacent to one another in the flattened gland. In some hypophyses the lumen of the original buccal evagination persists as a narrow residual cleft which may be expanded to form ciliated vesicles.Observations on cell size. nucleoplasmie ratio, degree of chromaticity in the nucleus, staining reactions of the cytoplasm and secretory granules, and the presence of chondriosomes, secretory granules, and vesicles in the cytosome are recorded. Secretory cells and histiocytes are idintified. Sceretoty cells are found in successive stages of growth, differentiation, secretion, and degeneration. Cells which have discharged their secretion apparently do not resynthesize secretory granules. Mitosis is not observed. The available evidence suggests utilization of a large supply of embryonic cells as the source of the fully differentiated cells. The cells of the pars intermedia are interpreted as potential secretory cells which do not differentiate under the inadequate nutrient conditions of that region.
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  • 10
    Electronic Resource
    Electronic Resource
    Philadelphia : Wiley-Blackwell
    Journal of Cellular and Comparative Physiology 13 (1939), S. 31-37 
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 3 Ill.
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