THE ENTOMOLOGIST. 493 



them. Owen believes the antennse to have the faculties of 

 touch and hearing, but thinks their precise function has not 

 been hitherto well defined. Thus, authors seem to differ 

 greatly as to the seat of the organs of the senses of touch, 

 smell, and hearing. 



Under these circumstances it appears to me that our best 

 guide to the elucidation of these difficulties lies in accurate 

 observations on the nervous systems of the insect tribes. 

 They differ greatly in their habits and manners, and we may 

 therefore naturally expect to find them varying in their 

 nervous structures in a corresponding degree. In the higher 

 class of animals we find the senses of hearing, feeling or 

 touch, and seeing, have each their appropriate set of nerves, 

 and that their nervous systems are much more complicated 

 than in insects ; but I am not aware that it has ever been 

 demonstrated by anatomists that the same nerve or nervous 

 system serves two different senses, and it is not reasonable to 

 expect such to be the case among insects. In the case of the 

 optic nerve, we find in insects, as in the higher animals, that 

 it serves the eye only. In many other warm-blooded 

 animals we find an exceedingly complicated division of the 

 nervous system, which in them are exceedingly sensitive to 

 injury, producing agonising sensations of pain; but that this 

 is not the case among insects we have numerous observations 

 recorded to establish that fact. Perhaps one of the most 

 striking instances is the experiment of Mr. Davis, an entomo- 

 logist well known to the members of the Entomological Club 

 of London, many years since. I heard him relate that while 

 out insect-hunting he took a large Libellula, and while 

 holding it by its wings, pressed together over its back, he 

 presented a finger to its mouth, and the insect made a 

 vigorous attempt to bite it, so he turned up the end of its own 

 tail to its mouth, and it bit a piece off of it, and this it 

 repeated several times. Mr. Davis at once came to the 

 conclusion that there was no feeling of pain in the operation. 

 He then, with a pair of scissors, removed nearly the whole of 

 that part of its body, and cutting a short length off a straw he 

 thrust it into the stump of the tail, but he found at first that 

 the artificial tail was too heavy, so he trimmed it until it 

 became a fair balance to the body. Away flew the Libellula, 

 and he commenced hawking about for flies just as if nothing 

 extraordinary had happened to its tail. 



