THE MUTATION THEORY 117 



mentioned by de Vries, and if Goldschmidt's account of the 

 cytology is confirmed, these must presumably be referred to the 

 influence of the maternal cytoplasm. Clearly this new work 

 opens up lines of exceptional interest. The interpretation I 

 have offered above must probably be reconsidered. The dis- 

 tinction between the male and female cells of the types may no 

 doubt be ultimately factorial, but it is difficult to regard such a 

 distinction as created by a differential distribution of the ordinary 

 factors. 



