The Inheritance of “Acquired” Characters

Abstract

DR. BASTIAN is unaccountably mistaken. Nothing in my letter indicates that I “assume (in the face of multitudinous difficulties) that the germ cells of all human beings are potentially alike.” I have no doubt that germ cells differ, and therefore that the individuals which arise from them would vary even were they reared under absolutely identical conditions. These germinal differences between individuals and species are rightly termed innate. Individuals differ also because they are exposed to unlike influences during development. These differences, due to the unequal play of stimuli, are rightly termed acquired. But in my letter I did not allude to differences between individuals, nor even to acquired differences between one side of the body and the other. I merely discussed the question whether the terms “innate” and “acquired” correctly distinguished between certain classes of characters. I gave reasons for believing that a nose is no more innate and inheritable than a scar on it. If Dr. Bastian thinks I am in error, will he indicate in what sense the scar is less inborn and more acquired than the nose?