22 



GENETICS AND EUGENICS 



gradually biologists have been coming to the view that Weis- 

 mann is right. The consequences of this view are very im- 

 portant not only as regards evolution in general, but also as 

 regards education, for if Weismann is right scholarship is not 

 inherited, but only capacity to learn. The son must begin in 

 his education, not where his father left off, but at the alpha- 

 bet, and he will not learn any faster because his father was 

 educated. I think the experience of educators justifies this 

 view. Children growing up in cultured homes have a certain 

 educational advantage due to their environment, but not to 

 heredity. Thus Darwin's attention was directed toward nat- 

 ural history, by the home environment in which he grew up. 

 The same is true in even greater degree of his sons, three of 

 whom have become distinguished scientists. It is very im- 

 probable that he inherited a taste for natural history, as he 

 supposed. More likely he acquired such a taste. 



Fig. 1. Diagram showing the relation of the body or soma (S) to the germ-celb 

 (G) in heredity. (After E. B. Wilson.) 



Besides showing that there is no sufficient evidence that 

 acquired characters are inherited, Weismann pointed out 

 anatomical and physiological reasons why we should not 

 expect them to be inherited. In the higher animals and 

 plants reproduction takes place not by division of the body 

 but by the development of special reproductive cells, eggs, 

 spores, and the like. The fertilized egg-cell of an animal be- 

 gins its development by dividing into two cells; these divide 

 into four, and so on. Sooner or later we notice that these cells 

 are not all alike. Some of them develop into muscles, others 

 into bone, or nervous tissue; in short they become differ- 

 entiated to form the various parts and tissues of the body, all 

 except some few which remain undifferentiated like the origi- 

 nal egg-cell itself. These undifferentiated cells wiU in fact 



