GENETICS 105 



mosome occurs, then its descendants cannot be 

 expected to produce the same results, even though 

 they act upon the same cytoplasm as that of the 

 parent cell, nor should a constant cytoplasm neces- 

 sarily restore them to the previous condition. But 

 in the individual organism it is more than probable 

 that the body as a whole maintains its chromosome 

 complex; only this view is in harmony with the 

 common persistence of the entire complex in so- 

 matic cells. 



There is every reason to expect such a condition. 

 Each individual maintains a reproductive mecha- 

 nism which is of no fundamental value to it as an 

 individual. The claims of the species are great 

 enough to attain this end and we cannot logically 

 avoid the probability of a correlation between the 

 total activities of the individual and the link which 

 connects it with the species, viz., the reproductive 

 cells. The individual is, after all, the only manifes- 

 tation of the species as a complex of differentiated 

 characters; to argue that its self -maintenance ex- 

 erts no influence on the characters of the species is 

 to argue that it is a dissociated byproduct. 



One other matter of gene behavior is of great 

 importance in this study. Tliis I have taken up 

 previously as an application of the principle of use 

 and disuse which is well established in the case of 

 macroscopic living units. ^^ The theory may be 



^Am. Nat, Vol. LXI, pp. 251-265, 1927. 



