Identifier: hereditysex00morg (find matches)
Title: Heredity and sex
Year: 1913 (1910s)
Authors: Morgan, Thomas Hunt, 1866-1945
Subjects: Heredity Sex
Publisher: New York, N.Y. : Columbia University Press
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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made — if weexclude man — are the rat and the guinea pig. Thenext case is unique in that the ovary was transplantedto a male. Steinach removed the sex glands from the maleguinea pig and rat and transplanted into the sameanimals the ovaries of the female, which establishedthemselves. Their presence brought about remarkableeffects on the castrated male. The mammary glands,that are in a rudimentary condition in the male, be-come greatly enlarged (Fig. 71). In the rat the hairassumes the texture of that of the female. The skele-ton is also more like that of the female than the male.The size of the feminized rats and guinea pigs is lessthan that of normal (or of castrated) males andlike that of the female (Fig. 72). Finally, in theirsexual behavior, the feminized rats were more likefemales than like males. These cases are importantbecause they are the only ones in which success-ful transplanting of the ovary into a male has beenaccomplished in vertebrates. THE EFFECTS OF CASTRATION 141
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Fig. 72. — Two upper figures, normal male guinea pig to left, M, andhis brother, F, to right — a feminized male. Two middle and two lowerfigures, a normal male at M, and his feminized brother, F. (After Steinach.) 142 HEREDITY AND SEX OPERATIONS ON BIRDS In striking contrast to these results with mammalsare those with birds, where in recent years we havegained some definite information concerning the devel-opment of secondary sexual characters. I am fortunate in being able to refer to severalcases — the most successful on record — carried outby my friend, H. D. Goodale, at the Carnegie Lab-oratory at Cold Spring Harbor. One case is thatof a female Mallard duck from which the ovary wascompletely removed when she was a very young bird.Figure 16 illustrates the striking difference betweenthe normal male and the female Mallard. In thespayed female the plumage is like that of the male. Darwin records a case in which a female duck in herold age assumed the characteristics of a male,

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