344 



SENSE OF SMELL IN FISUEf. 



YI. 



On the Sense of Smell in Fishes : By M. C. Dumerll*. 



but this ques 

 tionable. 



Fundamental 

 propositions. 



hlad? of fishes Almost all the fishes hitherto observed have nostrils f . 



called nostrils. At least this name is given to two deep holes, which are ge« 



nerally found in the heads of these animals between their 



eyes and lips. These cavities have a single slender orifice ; 



and within they are lined with a mucous membrane, having 



numerous folds. The first pair of nerves from the braia 



enter into the substance of this membrane, ramify in it, 



Supposed to be and there terminate. Analogy therefore seems to indicate, 



the organ of ^j^^j ^j^g nostrils of fishes are particularly intended for the 



organ of smell, as in all other animals with vertebras. 



Against this opinion however, adopted by all naturalists 



and physiologists, I have some facts and reflections io 



offer, which perhaps will seem more consistent with our 



knowledge in comparative anatomy and physiology. 



I propose to show, that the organ of smell does not and 

 cannot exist in the mouths of fishes, from their manner of 

 breathing: that the organs, hitherto considered as adapted 

 to the sense of smell in these animals, are intended for the 

 perception of a sensation analogous to that of taste: and 

 that there can be no true smell for an animal habitually im- 

 mersed in a fluid. 

 "Nerves of sight, In animals with vertebrae, anatomy easily distinguishes 

 ^^*""S) a.n^ among the nerves, that lead to the organs of sight, hearing, 

 guishedj and smell, the trunks of those peculiarly intended to trans- 



but not those of mit the sensation : but it is not the same with the organ of 

 taste. We know indeed, that, at least among the mammalia, 

 thegustatory faculty resides in the surface of the tongue: but, 

 as this fleshy substance has other functions, and as its move- 

 ments are particular!}' connected with the organs of speech 

 and deglutition, it receives several nerves, and these greatly 

 ramified, proceeding from three different regions of the 

 brain. Hence anatomists have not been able precisely to 



♦ Mag. Enc. Sept. 1807, p. 99. Read to the Institute/ All. 

 gust, the 24th. 



t Except the cyclostomes, as the lampreys and sphagobranr 

 chix, which are not real fishes, as I shall show elsewhere. 



determine. 



taste. 



Different 

 nerves 

 lead to it. 



