Hormones and heredity; a discussion of the evolution of adaptations and the evolution of species; . TOfirO/SJE-SHELL Q BO(S BLACkC O BLACK OBO 6 reiLOivQ. BXQ ropro/S£SH£LL Q Yo6 ^ YELLOW O The sex must be determined therefore by thespermatozoa, as in the case of colour-blindness, etc.,in man, and the colour factor must always be in thefemale-producing sperm. SEX-CHARACTERS IN EVOLUTION 119 Sexual Dimorphism It is obvious from the above facts that howeverinteresting and important sex-Hnked heredity may be,it is not the same thing as the heredity of secondarysexual characters, and does not in t
Hormones and heredity; a discussion of the evolution of adaptations and the evolution of species; . TOfirO/SJE-SHELL Q BO(S BLACkC O BLACK OBO 6 reiLOivQ. BXQ ropro/S£SH£LL Q Yo6 ^ YELLOW O The sex must be determined therefore by thespermatozoa, as in the case of colour-blindness, etc.,in man, and the colour factor must always be in thefemale-producing sperm. SEX-CHARACTERS IN EVOLUTION 119 Sexual Dimorphism It is obvious from the above facts that howeverinteresting and important sex-Hnked heredity may be,it is not the same thing as the heredity of secondarysexual characters, and does not in the least explainsexual dimorphism. In the first place, the termsex-linked does not mean occurring alway>s ex-clusively in one sex, but the direct contrary—trans-mitted by one sex to the opposite sex—and in thesecond place there is no suggestion that the develop-ment of the character is dependent in any way onthe presence or function of the gonad. The problemI am proposing to consider is what light the factsthrow on the origin of the secondary sexual charactersin evolution. In endeavouring to answer this ques-tion there are only two alterna
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherlondo, bookyear1921
