104 Professor Agassiz on the 



the position assigned to Cicindela, which is placed at the 

 head. That group is the most carnivorous of the order. But 

 I do not think it right to assign to the carnivorous insects 

 the highest rank, if there is no other reason to consider them 

 as such than the fact, that among Mammalia the Carnivora 

 rank higher than the herbivorous animals. 



Far from inclining to such views, 1 am prepared to shew 

 that the very fact of the complication of their jaws, and the 

 multiplication of their parts, the greater resemblance which 

 those parts have to common legs, the immobility of the pro- 

 thorax, the hardness of their anterior wings, the frequent 

 deficiency of the lower wings, the similarity in structure be- 

 tween the jaws of the larva and those of the perfect insect, 

 are so many characters which assign to the Coleoptera a 

 lower rank than that of the Lepidoptera. 



Indeed, if we institute a comparison between Coleoptera 

 and Lepidoptera, we are struck with the greater resemblance 

 between the former when perfect, and the caterpillar, than 

 between the beetle and the butterfly. It may be said, that 

 the beetle preserves the characters of the larvse of other in- 

 sects, and assumes only wings and more developed legs in 

 addition, without reaching other successive metamorphoses, 

 — those other changes through which the caterpillar passes 

 before it is transformed into the perfect image. 



This being once granted, it must be acknowledged in ge- 

 neral, that chewing insects should rank lower than sucking 

 insects ; and we may perhaps find in the complete matamor- 

 phoses of the higher Haustellata sufficient data to carry out 

 this view in determining the relative position to be assigned 

 to all the orders of that class. 



Among the mandibulate insects, for instance, we have, 

 besides Coleoptera, the Orthoptera, Neuroptera, and Hy- 

 menoptera. Now, the Neuroptera, though undergoing me- 

 tamorphoses as complete, in many respects, as the Coleop- 

 tera, have larva? whose structure seems decidedly lower than 

 that of the Coleoptera, for they are mostly aquatic worms, 

 provided not only with powerful jaws and all the complicated 

 chewing apparatus of mandibulate insects, but also with 

 aquatic respiratory organs, namely true external gills simi- 



