6 THE CLASSIFICATION OF INSECTS 



Though the fact, that many Hymenoptera have caterpillar-like larvae, will at once 

 place them one stage higher, that is, nearer the Haustellata, some facts presently to 

 be mentioned, respecting the changes which caterpillars undergo before they pass 

 into the state of complete pupae, will establish more fully the value of this argument. 



There is, however, one order of chewing insects, the position of which is some- 

 what embarrassing ; I mean the Orthoptera. If the views expressed above are 

 correct, the very fact of their having chewing jaws will place them among the 

 Mandibulata, below the Haustellata. But what is the proper position to assign to 

 them among Mandibulata I They cannot be placed higher than the Hymenoptera, 

 for their jaws are completely masticatory. But their position in relation to Coleop- 

 tera and Neuroptera is difficult to determine. They undergo no change after they 

 have been hatched from the egg, except that of assuming wings. They are born 

 from the egg with an aerial respiratory system ; indeed, in a condition which is 

 already higher than that of the larvae of Coleoptera, and decidedly higher than 

 that of the Neuroptera. We should, therefore, look to the changes which these 

 animals undergo within the egg, to determine their true position. But upon this 

 point observations are still wanting. At present I am inclined to place them 

 above Coleoptera, as we generally find that the degree of perfection which the 

 young assumes before it is hatched corresponds, to a remarkable extent, with the 

 perfection of the animal in its general structure. And if it were not for the 

 peculiar structure of the jaws in Hymenoptera, I should not hesitate to place 

 Orthoptera highest among Mandibulata. Again, the perfection of the wings of 

 Hymenoptera leads so decidedly to a parallelism between them and some of the 

 moths, that I cannot help thinking the best arrangement is the one mentioned 

 above ; namely, Neuroptera lowest, next Coleoptera, next Orthoptera, and Hy- 

 menoptera highest. The peculiar piercers, with which so many Orthoptera are 

 provided to lay their eggs, remind us of similar apparatus in Hymenoptera, which 

 would go to substantiate the position now assigned to these two orders of insects, 

 in close juxtaposition. 



Let us now consider the different orders belonging to the division of the Haus- 

 tellata, which contains only three great groups, the Hemiptera, Diptera, and Lepi- 

 doptera. The order in which I have mentioned them above seems to me to be 

 that in which they should naturally be placed, according to their structure and 

 metamorphoses. If we can be guided by the changes which the highest of these 

 animals undergo, it will be perceived that among Lepidoptera we have the true key 

 for their natural arrangement. The larvae of this last group are hatched in a 

 condition far superior to that of the larvae of any other insects. Not only are they 

 all provided with aerial respiratory organs, but the different regions of their body 

 are already more fully marked out than in the larvae of any other insects, by the 

 different structure of their various legs, and by the decided distinction which is 

 introduced between the head and body. Moreover, their skin is variously colored, 

 and provided with a most astonishing diversity of external appendages. 



At first, these animals are voracious in their habits. Provided with powerful 

 jaws, they chew large quantities of food, mostly derived from the vegetable kingdom. 



