SMELL. 305 



token of their perceiving food, when it coiihl not 

 be seen by them, however near to them it was 

 brought.* 



It has been doubted whether fishes, and other 

 aquatic animals possess the sense of smell; in some 

 of the Whale tribe, indeed, neither the organ of 

 smell nor the olfactory nerves are found. f Some 

 physiologists have gone the length of denying the 

 capability of water to serve as the vehicle of odorous 

 effluvia. But as water is known to contain a large 

 quantity of air which acts upon the organs of respi- 

 ration, it is easy to conceive that it may also convey 

 to the nostrils the peculiar agents which are calcu- 

 lated to excite perceptions of smell. Fishes are, 

 in fact, observed to be attracted from great dis- 

 tances by the effluvia of substances thrown into the 

 water ; and they are well known to have a strong 

 predilection for all highly odoriferous substances. 

 Baits used by anglers are rendered more attractive 

 by being impregnated with volatile oils, or other 

 substances having a powerful scent, such as assa- 

 foetida, camphor, and musk. Mr. T. Bellj has dis- 

 covered in the Crocodile and Alligator, a gland, 

 which secretes an unctuous matter, of a strong 

 musky odour, situated beneath the lower jaw, on 

 each side. The external orifice of this gland is a 

 small slit, a little within the lower edge of the jaw ; 

 and the sac, or cavity containing the odoriferous 



* Edinburgh New Journal of Science, ii. 172. The accuracy of 

 these results, which had been contested by Mr. Waterton, is fully 

 established by the recent observations and experiments of Mr. Bach- 

 man, vvhich are detailed in Loudon's Magazine of Natural History, 

 vii. 167. 



t Home ; Lectures on Comparative Anatomy, i. 17. 



I Phil. Trans, for 1827, p. 132. 



