Inheritance, Mendelism, and Mutation

Abstract

IN NATURE (August 18, pp. 780–84) appears an article by Prof. Goldschmidt on “The Determination of Sex.” The author supposes he is dealing with inheritance. At any rate, Mendelians suppose they deal with inheritance, and he declares “we may safely say that to-day, in the light of Mendelism and the work accomplished in the realms of cytology, the problem is solved as completely as the methods of biology permit.” Very probably trie odd chromosome of which he writes has influence; but very massive evidence indicates that sex is determined mainly, not by the nature, but by the nurture of the individual—by such things as hormones from the sex-glands, food, temperature, and the like. In other words, it is certain that both sets of sexual characters are inherited by the individual, but, except in true hermaphrodites and in “intersexuality” (abnormal blending), only one set is reproduced. Male is undeveloped female, and vice versa. There is alternative patency and latency, alternate reproduction, not alternate inheritance. But the alternation is often irregular. For example, in aphides, during a long and indeterminate series of generations, the male characters are latent.