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  • 1935-1939  (4)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 57 (1935), S. 31-59 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The little capsules in which snails of this family deposit eggs are so durable as sometimes to be found adherent to museum specimens; hitherto, however, detailed descriptions of such capsules have been restricted to the capsules long known as made by Neritina fluviatilis in fresh waters of Europe. The present paper adds descriptions, with measurements and sketches, of Neritina reclivata from Florida, Neritina virginea, Neritina punctulata, Theodoxus mneleagris, Nerita peloronta, Nerita alticola, Nerita tesselata and Neritilia succinea from Jamaica, British West Indies.These capsules are found to be remarkable in that the digestive tract aids in their formation; that is, the capsules are made as secretions of the lower oviduct to which mineral particles are added, and these mineral particles are supplied from the intestine and stored up in a special sac opening into the oviduct. Moreover, the mineral particles are of twofold origin; in some Neritinas they come from the ooze taken in with the food and passed through the intestine; in some Neritas they come from the liver as calcospherites, to be passed through the intestine.It is hoped that the data given will aid future descriptions of capsules from other species till a firm foundation is built for utilization of these capsules as aids in taxonomy.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 60 (1936), S. 191-209 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Differing from hitherto known spermatophores, these are found to have the form of a loop with a thick body and the slender ends twisted together.Also one end bears a spiral row of triradiate spicules, unique in being chitinoid secretions. Each is formed within a vacuole of a cell of a small gland found in the males. The ends of the spermatophores hold sperms, but the main mass consists of granules of problematical value. Spermatophores after discharge are stored up within the female, where remnants of them remain indefinitely.For the first time stages in the formation of spermatophores were found within the males. The head organ in the male is found to be more complex than hitherto known in this genus. A special head organ in the female is described for the first time in this family. An hypothesis is advanced as to the possible use of these male and female head organs in transfer of spermatophores. The suggestion is made that in this family the spermatophores and their organs of transfer and of storage may serve as generic characters.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    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.
    Type of Medium: Electronic Resource
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  • 4
    Publication Date: 1935-01-01
    Print ISSN: 0016-7428
    Electronic ISSN: 1931-0846
    Topics: Geography
    Published by Wiley
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