2o8 Variations and Orthoplasy 



of the organism as having very far-reaching and often un- 

 expected utilities. An adjustment, whose immediate utiUty 

 is that it supplements and screens incipient characters, 

 may by a slight change in the environment, or by support- 

 ing variations in a neighbouring part, or by another adjust- 

 ment of other organs, become part of a new system of 

 adaptations not at first accompHshed by it at all; there 

 may arise from the countless variations in shape, size, and 

 relation of parts, utilities that no one could have predicted, 

 and which only natural selection can and does discover ; 

 the very flexibility upon which the principle of organic 

 selection lays emphasis tends to reduce our expectation 

 that single lines of characters, coincident or other, will 

 appear, for by it all sorts of alternative and shifting utili- 

 ties are allowed to spring up. 



The Hmitation of the appHcation of the theory to coin- 

 cident variations would therefore, in the present writer's 

 opinion, serve to take from it much of its value, that is, 

 if * coincident ' be defined strictly, as it seems to be by 

 Professor Lloyd Morgan. If, however, we attempt to bring 

 all the phenomena under this term, it loses much of its 

 appropriateness ; for it would have to be defined to include 

 all functions and characters which might evolve in the 

 whole organism, in consequence of a particular accom- 

 modation, and become substitutes for the accommodation, or 

 i7i any way replace it. Accordingly, while the theory of 

 coincident variations is true and covers much of the terri- 

 tory, furnishing most valuable illustrations of the working 



muscular adjustments compensate for wear and tear on the teeth in the 

 individual's life, the evolution of the teeth, although screened by these ad- 

 justments, would nevertheless be by variations directly contrary to the modi- 

 fications wrought by their use. 



