Sex (electronic resource)

Description:

Identifier: b20442221 (find matches)
Title: Sex (electronic resource)
Year: 1914 (1910s)
Authors: Geddes, Patrick, Sir, 1854-1932.
Subjects: Sex
Publisher: New York : H. Holt and company London : Williams and Norgate
Contributing Library: Wellcome Library
Digitizing Sponsor: Wellcome Library

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g gonads(or testes) was only to be detected with themicroscope, though it was very profound.But gradually there came about a specialisa-tion of the accessory parts in relation to thedeeply different functions of egg-multiplyingand sperm-multiplying, and recognisably dif-ferent ovaries and testes were established.Furthermore, there came to be associated withovaries and testes a good deal of auxiliarytissue that had nothing directly to do withoogenesis or spermatogenesis. Accessoryglands and ducts were formed. It is probable that variations or mutationsinvolving the tissue in the vicinity of thereproductive organs have been from time totime caught up into their service, and it isnot necessary to suppose that these advan-tageous accessions, such as having a yolk-gland near the ovary, arose as pure coinci-dences. For it is a well-known fact (whether 46 SEX we understand it or not) that variations areoften correlated. It seems as if one germinalchange may have several inter-linked effects.
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Fig. 8.—The freshwater polyp, Hydra, hanging down froma leaf (L). It is about half an inch in length. Thediagram shows the tubular body; the tentacles aroundthe mouth; the male organs or testes (T) in very simpleexpression as minute knobs of cells; the ovary (OV), aprotruding nest of cells with one ovum (E). This idea requires to be extended to thebody as a whole. A somatic character, whichto begin with had nothing to do with sexualreproduction, may come into its service, and THE EVOLUTION OF SEX 47 be more or less changed in connection withits new function. Some investigators, suchas Tandler and Grosz and Kammerer, havegone the length of maintaining that all sex-characters have arisen from the transforma-tion of species-characters. Just as in theprimitive Metazoon body the cells lying nextthe gametes came by change of function intothe service of reproduction, so it may havebeen that more distant cell-complexes, whichhad already reached some degree of structuraldifferentiation and s

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