Classification of Insects. 103 



suckers to pump the more liquid nourishment upon which 

 they live. It has long been a question with me, whether the 

 nature of the metamorphoses or the structure of the jaws 

 was to be considered as the prominent character on which 

 to found the primary divisions. It struck me as possible, 

 that a classification, in which the chewing insects should be 

 brought together, and all sucking insects combined in another 

 group, and both of them subdivided according to their trans- 

 formations, might lead to as natural an arrangement as a 

 classification resting in its fundamental divisions upon con- 

 siderations derived from the metamorphoses alone. In order 

 to satisfy myself upon the importance of these two sets of 

 characters, I have examined the metamorphoses themselves, 

 which various groups of insects undergo, and have been 

 deeply impressed with the fact, that most of those insects 

 which undergo the so-called complete metamorphosis, are 

 provided, in their early stages of growth, with a chewing 

 apparatus, which is gradually transformed into the various 

 kinds of suckers with which the perfect insects are pro- 

 vided. 



This led me to the question, whether the structure of this 

 peculiar apparatus for chewing food did not indicate, among 

 insects, a condition of existence lower than that of those 

 insects which assume, during their metamorphosis, another 

 type of jaws in the shape of a sucker. And upon that sug- 

 gestion I attempted an arrangement of the different orders 

 of insects, which seems to me not only more natural, but to 

 correspond more fully with the lessons of embryology. I pro- 

 pose the following classification : — 



I. Chewing Insects II. Sucking Insects 

 (Mandibulata). (Haustellata). 



Neuroptera, Hemiptera, 



Coleoptera, Diptera, 



Orthoptera, Lepidoptera. 



Hymenoptera. 



The reason why Coleoptera have been so universally con- 

 sidered as the highest among insects, is plainly shewn by 



