USES OF SENSE OF TASTE. 
397 
therefore, are evidently of the same hind 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 his 
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 
Kep tiles 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 Pishes it is for the most part absent. Many In¬ 
ver tebr at ed. animals possess a tongue; but its uses are for the 
most part mechanical. Thus the tongue of the Limpet is a 
