242 TRANSMISSION OF ACQUIRED CHARACTERS 



an organism, impossible to believe that the little items of im- 

 provement which are added generation after generation say 

 in a cricket's musical instrument can have had selection-value. 

 There are other difficulties on both sides, and it is likely to remain 

 for a long time a matter of opinion which side has the greater 

 difficulties to face. 



A Matter of Fact. It is plain, however, that what we have to 

 ask is whether interpretations in terms of modification-inheritance 

 have any basis in present-day experience, such as selectionist 

 interpretations have, for instance, in domestication on the one 

 hand and variation-statistics on the other. And our survey 

 seems to indicate that it is very difficult to find any empirical 

 basis whatsoever for the affirmative position. 



If modification -inheritance were known to be a fact it would 

 in nowise exclude interpretations in terms of natural selection 

 and other factors, for even the most thorough-going Neo- 

 Lamarckian will hardly maintain that his hypothesis, if verified, 

 would be an all-sufficient aetiological factor, and even the most 

 convinced Neo-Darwinians could not refuse to recognise an ad- 

 ditional factor if that were verifiable. There is no need to pit 

 one theory against the other in this fashion ; the more factors in 

 evolution that are discovered the better ! 



The question resolves itself into a matter of fact : Have we 

 any concrete evidence to warrant us believing that definite 

 modifications are ever, as such or in any representative degree, 

 transmitted ? It appears to us that we have not. But to say 

 dogmatically that such transmission is impossible is unscientific. 

 In regard to that, the truly scientific position is one of active 

 scepticism (thdtige Skepsis). 



14. Indirect Importance of Modifications 



Importance of Nurture. Scepticism as to the transmission 

 of acquired characters does not imply that we under-rate the 

 importance of " nurture." We have seen (i) that an appro- 



