Coincident Variation Theory not Sufficient 201 



§ 2. The Coincident Variation Theory not Sttfficient 



Just here there seems to be a point of difference ^ of 

 construction of the principle of organic selection ; or at 

 least a difference of emphasis, which results in giving it 

 somewhat different range. Professor Morgan defines the 

 principle as, in effect, ' the natural selection of coincident 

 variations,' ^ />., variations in the same direction as the modi- 

 fications by which they are shielded and with which they 

 are said, for this reason, to 'coincide.' In view of the 

 application of the principle pointed out above, the writer, 

 on the contrary, includes not only ' coincident ' but also corre- 

 lated variations. It is indeed true that the accommodations 

 and modifications, in so far as they are directly supplemen- 

 tary to an incomplete organ or function, open the way for 

 coincident variations; these, gradually appearing in the 

 direction of the modification, in time replace it. But ac- 

 commodation in many cases — indeed, possibly in most 

 cases — involves a complex mechanism, a complex group 

 of characters. It keeps alive not only the variations which 

 coincide with it in a particular function ; it keeps alive the 

 whole animal, and so screens all the characters which that 

 animal has. And various hnes of adaptation may be fos- 

 tered and screened by a single general accommodation. 

 This appears notably in the case of the intelligence. Intel- 

 ligence is what is called above a * blanket utility ' ; it comes 

 into play again and again to supplement the most varied 



If they did retain the harshness,, then that would be an illustration of what I 

 have indicated above : the same dependence on variations to get rid of the 

 character that there was in acquiring it, i.e., by reversed selection while or- 

 ganic accommodation was in operation. 



1 As between Professor Lloyd Morgan's views and the writer's; see, how- 

 ever, the * new statement ' made by Professor Morgan in Appendix A. 



2 Animal Behaviour ^ p. 115. 



