s a pleasant gospel that what we like is
really good for us, and, when we have made some small allowances for
artificial conditions, it is in the main a true one also.

The sense of taste, which in the lowest animals is diffused equally over
the whole frame, is in ourselves and other higher creatures concentrated
in a special part of the body, namely the mouth, where the food about to
be swallowed is chewed and otherwise prepared beforehand for the work of
digestion. Now it is, of course, quite clear that some sort of
supervision must be exercised by the body over the kind of food that is
going to be put into it. Common experience teaches us that prussic acid
and pure opium are undesirable food-stuffs in large quantities; that raw
spirits, petroleum, and red lead should be sparingly 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 automatic premonitory adviser upon the
kinds of food we ought or ought not to indulge in, we should naturally
commit considerable imprudences in the way of eating and drinking--even
more than we do at present. Natural selection has therefore provided us
with a fairly efficient 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 favourable attention eatable and wholesome ones;
and, on the whole, in 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 flavours 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 int