HEREDITY AND EVOLUTION lia 



I do not see how. Inability to form a clear 

 a priori conception of the process has in itself no 

 validity as an argument against the fact, if fact 

 it be. The progress of biological discovery has 

 repeatedly transformed apparent a priori impos- 

 sibilities into everyday realities. And if exper-| 

 iment shall really demonstrate the transmission 

 of somatogenic modifications the cytologist has 

 no fundamental obstacle to interpose. The 

 mechanism that his studies have revealed will ac- 

 count for the transmission of all forms of ger- 

 minal modifications, however they may be caused. 

 The question involved is not of the transmission 

 of the idioplasm or of the germ-cell, but of its 

 interaction with the soma; and this is not an 

 a priori question, but one of fact. Letjjs-admit 

 freely that such an interaction _as Darwin, .as- 

 sumed may be; a_real and potent factor in^hered- 

 ftyTl Eoupi itgives no hint of its existen ce in the 

 visible apparatus pf„ the cell, In the present 

 defective state of our knowledge we may well 

 grant that there may be many a thing between 

 germ-cell and body that is not yet dreamed of in 

 our biological philosophy. But has the trans- 

 mission of acquired characters, in the strict and 

 proper sense of that much abused phrase, been 

 demonstrated? If in closing I venture to ques- 

 tion this, I pray that my sins be not visited upon 

 the study of the cells, but upon a failure to dis- 

 cover the demonstration in other fields of inquiry. 



