FOOD AND FEEDING. 471 



ingly partaken of by the judicious feeder ; and that even green fruit, 

 the bitter end of cucumber, and the berries of deadly nightshade are 

 unsatisfactory articles of diet when continuously persisted in. If, at 

 the very outset of our digestive apparatus, we hadn't a sort of auto- 

 matic premonitory adviser upon the kinds of food we ought or ought 

 not to indulge in, we should naturally commit considerable impru- 

 dences in the way of eating and drinking — even more than we do at 

 present. Natural selection has therefore provided us with a fairly effi- 

 cient guide in this respect in the sense of taste, which is placed at the 

 very threshold, as it were, of our digestive mechanism. It is the duty 

 of taste to warn us against uneatable things, and to recommend to our 

 favorable attention eatable and wholesome ones ; and, on the whole, 

 in the spite of small occasional remissness, it performs this duty with 

 creditable success. 



Taste, however, is not equally distributed over the whole surface 

 of the tongue alike. There are three distinct regions or tracts, each 

 of which has to perform its own special office and function. The tip 

 of the tongue is concerned mainly with pungent and acrid tastes ; the 

 middle portion is sensitive chiefly to sweets and bitters ; while the 

 back or lower portion confines itself almost entirely to the flavors of 

 roast meats, butter, oils, and other rich or fatty substances. There 

 are very good reasons for this subdivision of faculties in the tongue, 

 the object being, as it were, to make each piece of food undergo 

 three separate examinations (like " smalls," " mods," and " greats " at 

 Oxford), which must be successively passed before it is admitted 

 into full participation in the human economy. The first examination, 

 as we shall shortly see, gets rid at once of substances which would be 

 actively and immediately destructive to the very tissues of the mouth 

 and body ; the second discriminates between poisonous and chemi- 

 cally harmless food-stuffs ; and the third merely decides the minor 

 question whether the particular food is likely to prove then and there 

 wholesome or indigestible to the particular person. The sense of taste 

 proceeds, in fact, upon the principle of gradual selection and elimina- 

 tion ; it refuses first what is positively destructive, next what is more 

 remotely deleterious, and finally what is only undesirable or over-lus- 

 cious. 



When we want to assure ourselves, by means of taste, about any 

 unknown object — say a lump of some Avbite stuff, which may be crys- 

 tal, or glass, or alum, or borax, or quartz, or rock-salt — we put the tip 

 of the tongue against it gingerly. If it begins to burn us, we draw it 

 away more or less rapidly, with an accompaniment in language strictly 

 dependent upon our personal habits and manners. The test we thus 

 occasionally apply, even in the civilized adult state, to unknown bodies, 

 is one that is being applied every day and all day long by children and 

 savages. Unsophisticated humanity is constantly putting everything 

 it sees up to its mouth in a frank spirit of experimental inquiry as to 



