Criticisms of Theory of Nahtral Selection. 359 



the first acted directly upon these structures them- 

 selves, Darwinists do not suppose that in all — or even 

 in most — cases of correlated growth the correlated 

 structures are of use. On the contrary, it is well 

 known that structures due to correlated growth are, 



Fig. 117.— Feather-footed pigeon. Drawn from nature. 



as a rule, useless. Being only the by-products of 

 adaptive changes going on elsewhere, in any given 

 case the chances are against these correlated effects 

 being themselves of any utilitarian significance ; and, 

 therefore, as a matter of fact, correlated growths 

 appear to be usually meaningless from the point of 



