THE BEGINNINGS OF LIFE. 60 1 



it as if it were as universal in its operation as the 

 general co-ordinating power above referred to, which 

 does more or less influence all forms of life. Again, 

 instead of looking upon '^organic polarity' as an ever 

 potent, co-ordinating power, which must infallibly 

 co-operate in producing the results that happen to 

 be initiated by any cause of change whatsoever, Mr. 

 Darwin seems to regard it as a more or less occa- 

 sional cause of changes otherwise unaccountable — 

 of which he gives many highly interesting examples 

 under the head of ^Correlated Variability^.' 



Having made out with admirable skill one of the 

 principal modes by which, in the course of time, higher 

 organisms are made to vary, Mr. Darwin seems unwil- 

 ling to admit that other agencies may occasionally be 

 much more potent — especially amongst lower organ- 

 isms. And yet internal causes, or molecular polarities, 

 are, as we have seen, almost the sole regulators of form 

 and structure amongst those multitudinous hosts of 

 lower organisms now included under the name of 

 Ephemeromorphs 2. These internal polarities, operating 



^ ' Animals and Plants under Domestication,' chap. xxv. 



2 As we have previously stated (p. 594), Mr. St. George Mivart is 

 also strongly impressed with the inadequacy of Natural Selection for 

 occupying the all-important position assigned to it by Mr. Darwin. He 

 has expressed his belief that there is some deep underlying and in- 

 ternal cause of change to which the influence of Natural Selection is 

 subordinate. Although we cannot agree with Mr. Mivart's teleological 

 views, we do agree with him as regards the importance to be attached to 

 these internal causes of change. In one of the most interesting chapters 



