OF THE SKELETON. 141 



life of the animal. The only rational suggestion on the 

 subject is, that in addition to the sense of touch, they are 

 either endowed with another sense of which we are igno- 

 rant, or with the sense of smell; the latter is rendered 

 more probable from their situation between the eyes and 

 mouth, and almost close to the latter : this in vertebrate 

 animals may be considered the usual site of the nostrils. 

 Professor Rennie considered the antennae to be the organs 

 of hearing, and called them ears without hesitation ; his 

 theory has been embraced by two subsequent writers, a Mr. 

 Clarke, of Birmingham,* and Mr. Newport, of London,f 

 but these writers have not adduced any fact either in the 

 structure of antennae, or the mode of using them, that at all 

 bears out this view of the subject. It is very certain that 

 their general office is that of tactors, and if we seek to add 

 other powers we should be careful to ascertain that their 

 structure is adapted to the office we wish to assign them, for 

 each organ is found by anatomists to be admirably fitted 

 for the functions it has to perform, and the form and solidity 

 of the antennae precludes the possibility of their conveying 

 sound. 



The second segment is the prothorax ; it is very large 

 in the common cockchafer, and indeed in all beetles, and 

 in this class appears to receive the head as in an excava- 

 tion or cup : in a locust or cricket it is equally large, but 

 in a butterfly, fly, or bee, it is narrow, and scarcely percep- 

 tible : in bees, and most Hymenopterous insects, consid- 

 erable doubt has been expressed by entomologists as to its 

 extent, and much discussion has taken place on the ques- 

 tion, which however is of interest only to those who wish 



* * Magazine of Natural History,' New Series, Vol. ii. p. 472. 

 f ' Transactions of the Entomological Society of London,' Vol. II., 

 p. 229. 



