CHAPTER XIV 



Coincident and Correlated Variations and 

 Orthoplasy 



§ I. Correlated Variations 



In the preceding pages I have neglected, except by 

 implication, the topic of the correlation of variations and 

 of characters, refraining from asking the question of the 

 locus of utility in the various spheres in which organic 

 selection is supposed to be a real influence. It must have 

 occurred to the reader, however, to ask whether the princi- 

 ple is not limited in its application to those modifications 

 which confer direct utility upon certain variations. For 

 it may be said that unless a given variation be made of 

 direct utility by modification or accommodation, it would 

 not be saved, nor would its possessor propagate his kind 

 and so perpetuate such variations. 



This is a pertinent inquiry ; it indicates the limitation of 

 the principle in all cases in which the perpetuation of a 

 single variation of definite type depends upon the value 

 of modification of the same sort. But just at this point 

 the question of correlation comes in. A creature may be 

 kept alive — and with him a great variety of characters may 

 be perpetuated — through his accommodation and modi- 

 fication in some respect which may seem to have no bear- 

 ing upon the particular character whose origin we are 

 concerned to investigate. Creatures with better breath- 



196 



