CLASSIFICATION OB INSECTS. 19 



the larva molts and assumes a second form with shorter legs and 

 m.mdibles and soft skin; it is.still distinctly of the campodeilorm 

 type, however, and similar to the larva- of a number of other 

 rather primitive families of beetles, and hence termed "cara- 

 boid" from the family Carabida?. After another molt aimilirr 

 larva appears, very similar to that of the family Scarabanda?, 

 and suitably known as the scarabaeoid larva. The next stage is 

 formed in a smooth cavity in the soil ami is characterized by a 

 more or less rigid, curved body; it is known as the coarctate 

 larva and usually undergoes hibernation. In the spring, the 

 next larva is a return to the Scarabaeoid type which doee not feed, 

 but burrows about for a time and finally pupates after the manner 

 of other beetles. 



It is very evident that the several larval forms are beautifully 

 adapted to the varied conditions which the larva has to meet 

 during its development. They also follow a general course of 

 degredation and loss of activity as their life cycle, reproducing 

 in a general way the evident steps taken by evolution in the 

 transition from the campodeiform to the apodous type. There 

 is one anachronism, however, in relation to the scarabasoid larvae. 

 If, as appears to be true, this is really similar to the larva so 

 named in the family Scarabaeidae, it can not bear any genetic 

 relationship, since the Lamellicornia, to which the Scarabaeidae 

 belong is a very highly specialized group which could not be 

 derived from the otherwise greatly specialized Meloidae that are 

 the offshoot of another group of beetles. Likewise we cannot 

 imagine a derivation in the opposite direction. We are forced, 

 therefore, to the conclusion that this specific larvae is only a re- 

 sponse to similar stimuli in the environment in the two insects. 

 Such a case serves well to illustrate that in larva? as in adults the 

 appearance of similar structures through convergence may easily 

 lead to misconceptions. This example is more striking than the 

 independent appearance of triungulin larvae in widely separated 

 groups, for as we have seen the triungulin is a very generalized 

 larva of the campodeiform type. 



LITERATURE. 



This list is in no sense a bibliography. It includes only the few papers cited 

 as of special interest in the present connection. 



