The effects of semi-spaying and of semi-castration on the sex ratio of the albino rat (Mus norvegicus albinus) / Helen Dean King.

  • King, Helen Dean, 1869-1955.
Date:
1911
Catalogue details

Licence: In copyright

Credit: The effects of semi-spaying and of semi-castration on the sex ratio of the albino rat (Mus norvegicus albinus) / Helen Dean King. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    5/14 (page 383)
    son. Many of the writers of these papers stated their belief in the theory that sex is determined in the ovary, but very few of them put any faith whatever in von Seligson’s contention that male eggs are segregated in the right ovary and that female eggs are produced only in the left ovary. Goenner (’96) repeated von Seligson’s experiments on rabbits, and also extended them. He removed one testicle from each of four males and one ovary from each of five females, all of the ani- mals being about six months old when the operation was per- formed. From the various matings in which animals were paired that lacked the gonad on the same side of the body Goenner obtained only three litters, each of which contained both males and females. Four of the 16 young contained in these litters died before their sex was ascertained; of the remaining 12 animals, four were females and eight were males. These results indicate that von Seligson did not properly distinguish the sexes of the individuals in the various litters that he examined; but they do not give convincing evidence against his theory, since unfortun- ately Goenner does not state whether he killed the females and ascertained if the gonads had been entirely removed by the oper- ation. Dawson’s revival of the right and left ovary hypothesis for man has one important modification: the spermatozoan is not con- sidered to have any influence whatever in determining sex. According to Dawson’s theory, therefore, spermatozoa from either testicle are able to fertilize eggs from either ovary. Cal- houn is of the opinion that the spermatozoan may possibly have something to do with sex, and she suggests that this matter be investigated experimentally. Evidently this writer is unac- quainted with much of the literature dealing with the question of sex-determination in the higher forms. In order to test the truth of Dawson’s hypothesis, Doncaster and Marshall (’10) made a small series of experiments last spring- on the albino rat. One female was spayed on the right side, and a second one on the left. As soon as these rats had recovered from the effects of the operation, they were mated with normal males. The female that was spayed on the right side gave birth