120 COJIPARISONS OF STRUCTURE IN ANDIALS. 



launch their tongue at insects, (the mode in 

 which they take their prey,) and attain their 

 mark -with extraordinary velocity and pre- 

 cision, the sense of touch, we can scarcely 

 doubt, resides in that organ. In tortoises and 

 turtles, Ave may, perhaps, look for this sense in 

 some degree about the lips and muzzle, for, 

 on touching those parts, they generally with- 

 draw the head into the shell. 



Fishes do not possess any special organs of 

 touch, unless, indeed, the cirrhi, or barbels, of 

 soft flesh about the mouths of some' species may 

 be considered as such, and also the long fila- 

 ments which we have described as arising from 

 the head of the angler, and "\nth which it is 

 said to entice its prey. 



As w^e have adverted to insects, we may here 

 take the opportunity of again noticing them, 

 with reference to the sense of touch. We have 

 alluded to the evident proofs of sensibility in 

 the feet of the common fly, in the crane-flies 

 also, the limbs are organs of touch;* but in 

 these insects the antennte are short, for it is 

 certainly in the antenns generally that the 

 sense of touch most eminently dwells. 



jMany insects, as they run along, make inces- 

 sant use of their antenna' 5s feelers. The 



