284 Studies in the Theory of Descent. 



is readily conceivable that a change in the condi- 

 tions of life, such, for instance, as removal to a 

 new food-plant, would bring about the adapta- 

 tion of the adult larva as its chief result. 



I shall next proceed to show how far the as- 

 sumption here made that all markings depend 

 on natural selection is correct. 



