i8 4 INSECTS 



it not infrequently follows as the result, and it is not 

 by any means easy, even for man himself, to guard 

 against injury in all cases. 



We see also that parasitism is not by any means a 

 primitive condition but an adaptation, frequently 

 accompanied by specialization of a high order. It is, 

 in some of its manifestations, of comparatively recent 

 origin, the greatest diversities obtaining in the highly 

 specialized Diptera, while the simple forms are all 

 in the more generalized orders, being there little more 

 than an adaptation to life on an animal rather than 

 on a plant. 



