450 Darzvin, and after Darwin. 



— so essentially important for his theory— he does not even 

 attempt to show. Lastly, and quite apart from these remarkable 

 oversights, even if Mr. Tylor's hypothesis were as reasonable and 

 well-sustained as it is fanciful and inadequate, still it could not 

 apply to sexual colouration : it could apply only to colouration 

 as affected by physiological functions common to both sexes. 

 Yet it is in order to furnish a " preferable substitute" for Mr. 

 Darwin's theory of j'^;r«/(// colouration, that Mr. Wallace adduces 

 the hypothesis in question as one of "great weight"! In this 

 matter, therefore, I entirely agree with Poulton and Lloyd 

 Morgan. 



