CharacU 'i as Adaptive and Specific. 241 



Consequently, if there be any reason for believing 

 that climatic characters may become in time here- 

 ditary characters, the doctrine in question would 

 collapse, even supposing that all specific types were 

 to be re-constituted on a basis of experimental 

 inquiry, for the purpose of ascertaining which of 

 fhem conform to the test of Heredity. Now there 

 are very good reasons for believing that climatic 

 characters not unfrequently do become hereditary 

 characters ; and it was mainly in view of those 

 reasons that I deemed it worth while to devote so 

 much space in the preceding chapter to the facts of 

 climatic variation. I will now state the reasons in 

 question under two different lines of argument. 



We are not as yet entitled to conclude definitely 

 against the possible inheritance of acquired char- 

 acters. Consequently, we are not as yet entitled 

 to assume that climatic characters — i. e. characters 

 acquired by converse with a new environment, con- 

 tinued, say, since the last glacial period — can never 

 have become congenital characters. But, if they ever 

 have become cong.'nital characters, they will have 

 become, at all events as a general rule, congenital 

 characters that are useless ; for it is conceded that, 

 qud climatic characters, they have not been due to 

 natural selection. 



Doubtless the followers of Weismann will repudiate 

 this line of argument, if not as entirely worthless, 

 at all events as too questionable to be of much 

 practical worth. But even to the followers of Weis- 

 mann it may be pointed out, that the Wallacean 

 doctrine of the origin of all specific characters by 

 means of natural selection was propounded many years 



II. li 



