58 THE DOCTRINE OF IMMORTALITY 



heredity, a view which many eminent investigators have 

 since defended. We must today admit that the nucleus plays 

 a part in heredity, but not an exclusive role. The investiga- 

 tions of two Americans, ConkHn^^ and Lillie,^^ furnish the 

 proof that in certain cases distinct regions can be distin- 

 guished in the protoplasm of the undeveloped ovum. When 

 the development proceeds each of these regions plays a special 

 role in the formation of the body. It is possible to alter the 

 normal distribution of the substances, which are character- 

 istic for the regions, without killing the ovum. This is 

 accompUshed by the centrifuge. ConkJin has succeeded in 

 observing in centrifuged eggs that the substances, which have 

 acquired a new position in the ovum, nevertheless form the 

 same structures as before. From these observations he draws 

 the just conclusion that organ-forming substances are present 

 in these ova from the beginning. That which arises in the 

 course of the development of the new individual is, in these 

 cases, certainly determined at least in part by the protoplasm 

 of the ovum. Hence we must admit that the protoplasm also 

 participates in heredity. I do not see how we can accept 

 the theory that the nucleus is exclusively the organ of heredity. 

 On the contrary we must say that the essence of reproduction 

 is the continuation of the growth of immortal protoplasm. 

 The history of protoplasm is uninterrupted, and therefore we 

 say: the immortality of the protoplasm and of the nucleus is 

 also the explanation of heredity. 



