Characters as Adaptive and Specific. 279 



regards Isolation, much more remains to be said in 

 the ensuing portion of this work, while, as regards 

 Climatic Variation, there are literally innumerable 

 cases where changes of specific type are known to 

 have been caused by this means. 



7. To the latter class of cases, however, it will be 

 objected that these changes of specific type, although 

 no doubt sufficiently " stable " so long as the changed 

 conditions remain constant, are found by experiment 

 not to be hereditary ; and this clearly makes all the 

 difference between a true specific change and a merely 

 fictitious appearance of it. 



Well, in the first place, this objection can have 

 reference only to the first two of the five principles 

 above stated. It can have no reference to the last 

 three, because of these heredity constitutes the very 

 foundation. This consideration ought to be borne in 

 mind throughout. But now, in the second place, even 

 as regards changes produced by climate and food, the 

 reply is nugatory. And this for three reasons, as 

 follows. 



(a) No one is thus far entitled to conclude against 

 the possible transmission of acquired characters ; and, 

 so long as there is even so much as a possibility of 

 climatic (or any other admittedly non-utilitarian) 

 variations becoming in this way hereditary, the reply 

 before us merely begs the question. 



(b) Even supposing, for the sake of argument, that 

 acquired characters can never in any case become 

 congenital, there remains the strong probability 

 sanctioned as such even by Weismann that changed 

 conditions of life may not unfrequently act upon the 

 material of heredity itself, thus giving rise to specific 



