A Possibility 113 



be so not from any inherent difficulty in mak- 

 ing a change in it, but from the difficulty of 

 getting the germ plasm in which the change 

 has been made into a position where it can be 

 fertilized, and thus permit of its continuation. 

 The changed germ has a brilliant record as 

 the source of consciousness, but it must lead 

 the life of a celibate and leave no progeny. 

 Professor Weismann assumes that there is 

 a doubling division of the cell, in which each 

 resulting mass is precisely like the other, and 

 also differentiating divisions, by which one set of 

 determinants is marshalled in one portion, and 

 the other set in the other portion. Doubling 

 divisions yield germ cells, and differenti- 

 ating divisions yield somatic cells. Professor 

 Hertwig, in opposition to this, affirms that all 

 divisions are doubling divisions. 1 I am in- 

 clined to take the other alternative and affirm 

 that all divisions, except in the simplest organ- 

 isms, are differentiating. Growth must be 

 dominant to produce a group of related cells, 

 and while it is dominant, the complexity of 

 relations and the increased strength of the 



1 See his " Biological Problem of To-day," p. 77. 



i 



