Dr. August Weismann on the Importance of Sexual Reproduction for the theory of Selection ¹

Abstract

IN NATURE, vol. xxxiii. p. 154, was given an article on Prof. Weismann's most interesting and important memoir on “The Continuity of the Germ-Plasma considered as the Basis of a Theory of Heredity.” The present memoir also abounds with interest, and may be regarded as following naturally from the former one as a continuation and further elaboration of some of the questions raised in it. The main aim of the memoir is to establish the position that the process of sexual reproduction is the prime agent by which all the varied differentiations of the complicated phyla of the Metazoa has been brought into existence. A strong part of the argument is devoted to the establishment of the position that peculiarities acquired by the parent are not transmitted to the offspring, and to showing that the hypothesis that such acquired peculiarities are transmitted is not necessary for the explanation of the known phenomena of heredity and the mode of origin of the series of organic forms. It will be remembered that the assumption of this position forms an important and necessary factor in the theory of the continuity of the germ-plasma, but it was one which in the former memoir was only lightly touched upon.