DISTEIBUTE INSECT VARIETY. 317 



and in others it approaches that of certain moths. Necromorpha^ 

 in which the pupa is provided with mouth, and organs of 

 locomotion detached from the trunk throughout their length, 

 but so swathed and enveloped in separate cases that it can 

 employ neither; this group includes the bees and beetles. 

 Isomorpha, which in all states is active and voracious, of similar 

 form to the imago except as regards wings, includmg bugs and 

 grasshoppers. Lastly, the Heteroptera, which, from its earliest 

 situation, possesses characters of all the rest as well as some 

 peculiar to itself. It includes the Stegoptera, which have a 

 necromorphous j^upa, and the dragon-flies, which have an 

 isomorphous pupa. 



It was held by Cuvier and Lamarck that the development 

 of the nervous system corresponds with the degrees of intelli- 

 gence in the same way as that of the circulatory system does ; and 

 that in successively reviewing the different families every organ 

 simplifies by degrees, loses energy, and finishes by disappearing 

 and confounding itself with the mass. Here, then, it would "be 

 natural to seek, as in Mollusca, characters in the organs of sensa- 

 tion, and the investigations undertaken to determme the 

 existence of auditory structures detailed in this volume may serve 

 to indicate a maximum of specific volition in certain groups of 

 European insects and a rank in genera and class, although the 

 results signally fail to elevate any one order in entirety, or to 

 arrange them in linear precedence as one is accustomed to regard 

 them in modern classification. Next to the auditory the ocular 

 organ may be looked to for structural characters, and the 

 investigations commenced by Johannes Mtiller, and carried on 

 by others, may shed some further light when taken in conjunc- 

 tion with actual observation. So also in regard to the senses of 

 smell and touch. 



The presence of auditory organs and well-developed eyes, 

 then, places the genera of grasshoppers and crickets representing 

 the Orthoptera Saltatoria first in the list. These would be 

 followed by Homoptera, represented by the genera of Cicada?, 

 which have the auditory organs greatly developed in the males, 

 but with whom sight appears less potent. Next to these 

 appear to rank the moths of the Noctuina, Bombycina, and a 

 few of the Geometrina, which have complex auditory organs. 



