348 SENSE OF SMELL IN FISHES. 



are discriminated by the tongue, when they are contained 



in a liquid ; and by the pituitary merabrancj when they are 



suspended in a gas. 



Smell peculiar From these general considerations of the nature of smells 



to the stale of and tastes, it appears, that liquids cannot intrinsically possess 



smell, since this quality of bodies is inherent in their state of 



and cannot be gas, or vapour. We are justified therefore in presuming, 



Equ d^^*^ ^^ ^ *^^* ^" animal, which from its nature must be immersed ia 



a liquid all its life, does not possess a sense of which it can 



make no use : and this is the case with cetaceous animals, 



fishes, most of the molluscae, a great number of crustaceous 



animals and worms, and all the zoophytes. 



Cetaceous tribe In a former paper I have pointed out the analogy be- 



analogous to . ^ , , ^ . , . , , , 



fishes in their tween nshes and cetaceous animals, with regard to the me- 



mode of respi- chanism of respiration*. It is in consequence of this mode 



' of respiration, if I may so say, and of their necessary abode 



in water, that the organ of smell appears to be annihilated 



in these animals ; for as Daniel Major and John Hunter 



first observed, though only in a few species, and Cuvier 



has since shown generally and more at large, there are no 



and want the olfactory nerves, and no ethmoidal foramina, in the ceta- 

 oUactory nerves. •' nii . , 



ceous animals. Ihe pituitary membrane, that lines their 



nostrils, is smooth, dry, and coriaceous : it appears to 

 have become insensible from the constant friction on it 

 ocsasioned by the rapid and violent action of the water, 

 that pervades the cavity of the nostrils. It appears how- 

 ever, that the organ of taste here supplies the place of that 

 of smell; for, by a slight modification of the organs, the 

 These nerves olfactory nerves of fishes may have another use, and be 



huTe another ^ggtine^ to make them sensible of tastes. 

 \ise 111 fishes. 



Though fishes From the ideas we have formed of the nature of smells, it 



cannot smell, necessarily follows, that fishes cannot receive impressions 



similar to those they occasion in animals that breathe air. 



they are sensi- Yet we know, that fishes are attracted by the emanations, 



blc of emana- ^j^^^ escape from several substances immersed in water, as 

 tons from sub- , i . /> , . i_ 



stances. is demonstrated by various baits employed in fishing ; the 



salted roes of cod and mackarel, the broiled or stinking 



flosh of certain animals, old cheese, and many other things 



of strong ^mell. 



* See Journalj vol. xxviii, p, 355. 



Aristotle 



