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  • Cell & Developmental Biology  (172)
  • Life and Medical Sciences  (172)
  • Analytical Chemistry and Spectroscopy
  • 1925-1929  (172)
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Year
  • 11
    Electronic Resource
    Electronic Resource
    Ant-mounds as to temperature and sunshine (1927)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 1-20 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ant Formica exsectoides F. builds mounds with some reference to sunlight, and measurements of internal temperatures have shown them higher in upper parts of the mound, but different in different faces of the mound - all higher than the earth outside the mound.Inside temperatures are not constant; they are due to the sunshine. The mound is so fabricated that the internal temperatures are conserved during the night. The ants make use of the differential internal temperatures for rearing broods.Some mounds show bilateral symmetry dependent upon sun exposure.Measurements of rate of running of these ants show a falling off with lower temperatures, and possibly this is one factor in the smaller development of northerly aspects of these mounds.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050440102
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  • 12
    Electronic Resource
    Electronic Resource
    Parental chromosome dimensions in Ascaris. A study of the effect of cellular environment on chromosome size (1927)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 117-125 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the early cleavage stages of Ascaris the homologous chromosomes are of unequal length. Measurements show that these homologues fall into two sharply defined groups suggesting their biparental origin. The shorter are considered to have come from the male.As the age of the embryo increases, these differences between the chromosome mates tend to become less, and it is suggested that at some later period in the history of the animal this difference will entirely disappear in response to the effect of continued existence in a common environment. The length of the chromosomes is very slightly shortened during the early cleavage divisions, while the area of the equatorial cross-section of the cells becomes enormously reduced.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050440106
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  • 13
    Electronic Resource
    Electronic Resource
    Oxygen consumption of individual pupae during metamorphosis (1927)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 313-339 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The rates of oxygen consumption of single pupae of blowflies (Phormia terraenovae, Phormia regina, Lucilia sericata), of the flesh fly (Sarcophaga sarracenioides Aldrich), of the Mediterranean flour moth (Ephestia kuehniella), and of the bee moth (Galleria mellonella) during metamorphosis, until emergence, have been determined. The record for each pupa, with the exception of those of blowflies, is practically continuous day and night during the period of pupal development which lasted from 140 to 300 hours, according to the species, at the temperatures used. During pupal development there is first a period of decrease in rate, which is later followed by a steady increase until a short time before emergence, when a sudden decrease occurs.The ‘oxygen curves’ of the blowfly pupae (Diptera) are quite different from those of the flour-moth and bee-moth pupae (Lepidoptera), although all are of the same general U-shaped type. There are strong indications of a specific difference in the curves of the blow-fly pupae. The flour-moth pupae curves differ slightly from those of the bee-moth pupae. During the major part of development the rates of O2 consumption of pupae of both sexes of bee moth and flour moth are about the same, but near the end of metamorphosis the females have higher rates than the males. No such sex difference appears among the dipterous pupae used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050440205
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  • 14
    Electronic Resource
    Electronic Resource
    The formation of contractile vacuoles in Amoeba proteus (1927)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 363-372 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The history of investigations on the contractile vacuole is reviewed briefly and brought up to date.The study of the contractile vacuole in Amoeba proteus is considered from standpoints of origin, structure, behavior, and function. The results are obtained from a prolonged study of normal organisms and from their reactions when introduced into conductivity water.The origin of vacuoles is studied by means of dark-field illumination which reveals the vacuole to be formed from a fusion and coalescence of extremely minute droplets.The retaining ‘wall’ of the contractile vacuole is not a permanent structure, but is in the nature of a condensation membrane, totally disappearing with each contraction.The loci of the contractile vacuoles are not permanent, but vacuoles are formed more or less at random. It is unlikely that they are supported in gelated areas, for amoebae with a dozen vacuoles are quite active and there is no interference with amoeboid movement.Conductivity water increases the size, number, and rate of contraction of contractile vacuoles, which suggests that they may function in maintaining an osmotic gradient as well as in the elimination of metabolic waste.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050440207
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  • 15
    Electronic Resource
    Electronic Resource
    Developmental modification and elimination of the larval stage in the ascidian, Corella willmeriana (1927)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 44 (1927), S. 467-514 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The eggs of Corella develop in the atrial chamber of the parent at a pH below that of normal sea-water (pH 7.4 ±). When removed to normal sea-water in early stages and under certain other experimental conditions, larval development is more or less inhibited, the tail being most inhibited, the dorsal region somewhat less. The free larval stage may be eliminated and later development and metamorphosis may proceed normally to an advanced stage in the chorion and give rise to normal ascidians. The region most inhibited are, in general, those which possess the highest reducing power, as indicated by KMnO4. Experiments made in the attempt to control development all agree in indicating that the early stages are adjusted to a certain CO2 concentration approximately that of the atrial chamber and presumably near that of the body. Solutions of the same pH may or may not inhibit development according to their CO2 content.The tail, the region of highest reducing power in the embryo during its development, is most inhibited; the dorsal region, the next most rapidly reducing region, is next in degree of inhibition. All differences in reducing power disappear when, or soon after, the animals are killed by other agents before treatment with KMnO4.
    Additional Material: 64 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050440305
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  • 16
    Electronic Resource
    Electronic Resource
    The comparative morphology of the secondary sexual characters of elasmobranch fishes. The claspers, clasper siphons, and clasper glands, together with a dissertation on the Cowper's glands of Homo. Memoir XIThe figures are executed from the author's dissections and preparations by Miss Edith C. Humphreys, to whom best thanks are tendered. (1926)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 42 (1926), S. 349-358 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The claspers of Centrina are adnate with the pelvic fin and bear a spine as in other Spinacidae. Mustelus canis resembles M. lunulatus rather than M. vulgaris. The claspers of Chiloscyllium end in a pointed spike. Pseudotriakis resembles the Carchariidae. The three North American Atlantic species of the genus Raia are considered, and R. laevis and R. erinacea are placed in the pseudogenus containing R. batis, and a new pseudogenus erected for R. ocellata. A gross and histological account is given of the Cowper's glands of Homo, and they are shown to be homoplastic with clasper glands, similar in structure, arrangement, development, and function.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050420112
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  • 17
    Electronic Resource
    Electronic Resource
    A new dorsal gland in the ground-squirrel, Callospermophilus, with a note on its anal glandThe author wishes here to acknowledge his gratitude to those who contributed to this investigation. The collection of dry skins in the American Museum of Natural History was placed at my disposal. The United States National Museum and the Museum of Vertebrate Zoölogy, University of California, kindly lent alcoholic specimens. The Museum of Zoölogy, University of Michigan, supported the field work. The use of the Alpine Laboratory of the Carnegie Institution of Washington was courteously granted. The author is indebted to Mr. C. H. Willey for his care in the preparation of the slides for microscopic study. (1926)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 42 (1926), S. 441-451 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the golden-mantled ground-squirrel, Callospermophilus, a spatulate glandular area has been noted in the skin of the back. It has been found in the following species: C. l. lateralis, C. l. arizonensis, C. l. caryi, C. l. saturatus, C. l. tescorum, C. c. chrysodeirus, and C. bernardinus. Probably it is common to the genus.The individual glands making up this area are modified and enlarged sudoriparous glands. They are divided into a tightly coiled and branched fundus, a large sinus, and a duct which passes caudad and outward to its exit at the surface.The glands secrete a strongly smelling oil, which is probably left on vegetation and other objects in the animal's environment and serves as a source of information to other members of the species. The glands are more active in spring and summer than in winter. They are stimulated by excitement. While present in both sexes, both adult and juvenile, they are best developed in adult males.Callospermophilus has three anal glands. These have flat-topped, straight-sided nipples which are protruded from the anus if the animal is frightened. A milky substance with a very weak odor can be extruded.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050420204
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  • 18
    Electronic Resource
    Electronic Resource
    Studies in mammalian spermatogenesis VI. The chromosomes of the rabbitContribution no. 201 from the Department of Zoölogy, University of Texas. The writer was aided in this study by a grant from The Committee for Research on Sex Problems of the National Research Council. (1926)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 43 (1926), S. 1-43 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The study is divided into three parts. Part I deals with the chromosome number and morphology in the amniotic cells of rabbit embryos. The number of chromosomes has been found essentially constant in amniotic cells of young, but more variable in older embryos. The somatic number is 44. Part II deals with the chromosomes of race crosses (Flemmish Giant X Polish) in which the homologous chromosomes were found to be alike. Part III deals with spermatogenesis. There are forty-four chromosomes in spermatogonia, and twenty-two in primary spermatocytes. The sex chromosomes are of the usual X-Y type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050430102
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  • 19
    Electronic Resource
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    Reversal of ciliary action in paramecium caudatumContribution from the Zoological Laboratory of the Johns Hopkins University and the Marine Biological Laboratory, Woods Hole. (1926)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 43 (1926), S. 105-117 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: 1Monovalent cation salts induce reversal in the direction of the stroke of the cilia; bivalent and trivalent cation salts with a few exceptions do not. Some acids induce reversal, others do not.2The duration of reversed action varies with the kind of salt and with the concentration. As the concentration increases, the duration of reversed action increases to a maximum and then decreases to zero.3Bivalent and trivalent cation salts neutralize the effect of monovalent cation salts. The relative amount required varies with the kind of salt used and with the concentration.4The amount of a given salt required to neutralize another salt is not proportional to the concentration of the salt neutralized. Weber's law does not hold.5The results seem to indicate that ciliary reversal is associated with differential adsorption and consequent changes in electric potential, but that there are also other factors involved.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050430106
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  • 20
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    Photoreceptors of Lumbricus terrestris, with special reference to their distribution, structure, and functionThis study was made at the zoölogical laboratory of The Johns Hopkins University and The Marine Biological Laboratory, Woods Hole, though chiefly at the former. (1925)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 41 (1925), S. 63-93 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A special type of cell, called ‘Lichtzellen’ by Hesse, was found in the photosensitive regions of the earthworm. Wherever the epidermis is most sensitive to light these cells are most abundant. They are found in the epidermis of all segments of the body and also in nerve enlargements of the prostomium and the caudal segment, but the intersegmental and ventral regions of the different segments, except the more distal ones, contain none of them. They are supplied by nerves and each contains a characteristic inner structure, the optic organelle, composed of a large central hyaline structure, the lens, which is surrounded by a dense network of nerve fibrillae, the retinella. In hanging drops the lens was found to focus light in the region of the retinella irrespective of the direction of the rays.These cells are similar in structure and function to the visual cells in leeches. Available data indicate that these cells function as photoreceptors and that the fibrillae of the retinella are the direct receptors of light stimuli.Pigment is not associated with the photoreceptors in a way that suggests direct functional relationship, but there is a subepidermal pigment layer through which pinhole windows admit light along the path of nerves to each of the nerve enlargements containing photoreceptor cells. These windows open in such directions as to determine the direction of withdrawal of the worm.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1050410105
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