USES OF SENSE OF TASTE. 397 



therefore, are evidently of the same kind with those of Touch, 

 differing from them only in the degree of sensibility of the 

 organ through which they are received ; and through these the 

 sense of Taste is more nearly related to that of Touch, than is 

 either of the other forms of special sensibility. 



502. This sense has a very important function in most 

 animals which possess it, that of directing them in their 

 choice of food. Most of the lower animals will instinctively 

 reject the articles of food that would be pernicious to them ; 

 thus even the voracious Monkey will seldom touch fruits of a 

 poisonous character, though their taste may be agreeable ; and 

 animals whose digestive apparatus is adapted to one kind of 

 food, will reject all others. It may be stated, as a general 

 rule, that substances of which the taste is agreeable to us 

 are useful and wholesome articles of food, and vice versd; but 

 there are many signal exceptions to this. It is interesting to 

 remark that in Man, when the reasoning powers are obscured 

 by disease, his instincts in regard to food often manifest them- 

 selves strongly, and frequently constitute the best guide in its 

 administration ; thus, there are many cases of fever in which 

 the physician is in doubt whether wine will be injurious or 

 beneficial, and in which he will usually find the disposition of 

 the patient to reject it, or his readiness to receive it, to be tiis 

 best guide. And in general it may be remarked that, in ill- 

 ness, the desire of the patient for food, or his disposition to 

 take it, pretty certainly indicate the fitness or unfitness of the 

 system to digest and appropriate it. 



503. The tongue presents nearly the same structure among 

 the Mammalia in general, as in Man ; but in Birds it is 

 usually cartilaginous or horny in its texture, and destitute of 

 nervous papillae, so that the sense of taste cannot be very 

 acute in any of those animals. Several of them use their 

 tongues for other purposes, the Woodpecker, for instance, 

 to transfix insects, and the Parrot to keep steady the nut or 

 seed which is being crushed between the jaws. In some 

 Reptiles the tongue is large and fleshy; in others long and 

 slender ; in others, again, it is almost entirely deficient : but 

 in no instance does it seem to minister to any acute sense of 

 taste. In Fishes it is for the most part absent. Many In- 

 vertebrated animals possess a tongue ; but its uses are for the 

 most part mechanical. Thus the tongue of the Limpet is a 



