262 SENSES OF INSECTS. 



resides, the only modes to which we can have recourse to 

 form any probable conjecture, are analogy and dissection. 

 At first, the opinion noticed above, that the palpi are its 

 organs, seems not altogether unreasonable ; but as the 

 argument from analogy, except as to their situation near 

 the mouth, is not in favour of them, and there seems no 

 call, were smell their function, for the numerous variations 

 observable in their structure, I think we must consider 

 them, as I have endeavoured to prove, rather as instru- 

 ments of touch. Let us now inquire, whether there be 

 not discoverable upon dissection, in the interior of the 

 head of any insects, some organ that may be deemed, 

 from its situation, under what we have called the nose 

 and nostrils, the seat of the sense we are treating of. 

 The common burying-beetle (Necrophorus Vespillo) is 

 an insect remarkable for its acuteness of smell, which 

 enables it to scent out and bury, as was formerly related 

 to you a , the carcases of small animals. Take one of 

 these insects, and kill it as formerly directed, examine 

 first its nose : in the middle of the anterior part you will 

 see a subtrapezoidal space, as it were cut out and filled 

 with a paler piece of a softer and more membranous tex- 

 ture. Next divide the head horizontally; and under the 

 nose, and partly under this space, which I call the rhi- 

 narium or nostril-piece b , you will find a pair of circular 

 pulpy cushions, covered by a membrane transversely 

 striated with beautifully fine striae. These are what I 

 take to be the organs of smell, and they still remain dis- 

 tinctly visible in a specimen I have had by me more 

 than fifteen years. A similar organ may be discovered 



9 VOL. I. p. 352. b VOL, III. p. 480. 



