Opinions on Isolation. 117 



"Amixia" thus very differently stated from that 

 of my "Independent Variability" (apogamy), or 

 Gulick's " Independent Generation " ; but, apparently 

 owing to this difference of statement, the principle 

 itself is not the same. In particular, while Weismann 

 holds with us that when new characters arise in 

 virtue of the mere prevention of intercrossing with 

 parent forms these new characters will be of non- 

 utilitarian kind 1 , he appears to think that divergence 

 of character under such circumstances is not likely to 

 go on to a specific value. Now, it is of importance 

 to observe why he arrives at this conclusion, which is 

 not only so different from that of Delboeuf, Gulick, 

 and myself, but apparently so inconsistent with his 

 own recognition of the diversifying effect of "Amixia'' 

 as regards the formation of permanent varieties. For, 

 as we have already seen while considering Darwin's 

 views on this same principle of " Amixia," it is highly 

 inconsistent to recognize its diversifying effect up to 

 the stage of constituting fixed varieties, and then not 

 to recognize that, so much divergence of character 

 having been already secured by the isolation alone, 

 much more must further divergence continue, and 

 continue at an ever accelerating pace - as Delboeuf 

 and Gulick have so well shown. What, then, is the 

 explanation of this apparent inconsistency on Weis- 

 mann's part? The explanation evidently is that, 

 owing to his erroneous statement of the principle, he 

 misses the real essence of it. For, in the first place, 

 he does not perceive that this essence consists in an 

 initial difference of average characters on the part of 

 the isolated colony as compared with the rest of their 

 1 Loc. dt., p. 54. 



