572 THE EVOLUTION OF LIFE. 



the question of the formation of species. But here we sec 

 that this question is a secondary and, in a sense, irrelevant 

 one. We are concerned with the production of evolving and 

 diverging organic forms; and whether these are or are not 

 marked off by so-called specific traits, and whether they will 

 or will not breed together, matters little to the general argu 

 ment. If two divisions of a species, falling into unlike con 

 ditions and becoming re-equilibrated with them, eventually 

 acquire the differences of nature called specific, this is but a 

 collateral result. The essential result is the formation of 

 divergent organic forms. The biologic atmosphere, so to 

 speak, has been vitiated by the conceptions of past natural 

 ists, with whom the identification and classification of species 

 was the be-all and end-all of their science, and who regarded 

 the traits which enabled them to mark off their specimens 

 from one another, as the traits of cardinal importance in 

 Nature. But after ignoring these technical ideas it becomes 

 manifest that the distinctions, morphological or physiological, 

 taken as tests of species, are merely incidental phenomena. 



Moreover, on continuing thus to look at the facts, we shall 

 better understand the relation between adaptive and specific 

 characters, and between specific characters and those many 

 small differences which always accompany them. For during 

 re-equilibration there must, beyond those changes of struc 

 ture required to balance outer actions by inner actions, be 

 numerous minor changes. In any complex moving equi 

 librium alterations of larger elements inevitably cause altera 

 tions of elements immediately dependent on them, and these 

 again of others: the effects reverberate and re-reverberate 

 throughout the entire aggregate of actions down to the most 

 minute. Of resulting structural changes a few will be con 

 spicuous, more will be less conspicuous, and so on continu 

 ously multiplying in number and decreasing in amount. 



Here seems a fit place for remarking that there are certain 

 processes which do not enter into these re-equilibrations but 

 in a sense interfere with them. One example must sufficu. 



