eyes
and ears claim a share, but they are not far off.

Now it is being recognised more and more clearly by medical and
physiological science that when the mind is much directed to any part of
the body it exercises an influence in some way not understood on the
flow of blood to that part to a degree which may seriously affect its
functions and even its growth. When a person is suffering from any
nervous affection, from heart disease, or even from weakness of the
eyes, it is of the utmost importance to keep him from knowing it if
possible, for if he knows it he will think about it, and that will
inevitably aggravate it. This principle is well recognised in systems of
physical culture. And surely it is impossible that so much intelligence
should pass through that one sensitive region of the body which we are
considering without affecting its growth and structure. Every muscle in
it becomes quick to respond to various sensations in different ways,
till the very recollection of those sensations will excite the same
response.

Nay, we may go further. The mental emotions excited by those sensations
will be expressed in the same way. For example, the sense of smell is
peculiarly effective in exciting disgust. Anything which does violence
to the sense of hearing exasperates, but does not disgust. If a man
practises the accordion all day in the next room you do not loathe him,
you only want to kill him. But anything that stinks excites pure
disgust. Here you have the key to the fact that disgust and all feelings
akin to it, disdain, contempt and scorn, express themselves through the
nose. Darwin says that when we think of anything base or vile in a man's
character the expression of the face is the same "as if we smelled a bad
smell." This is an example of the temporary expression of a passing
emotion, and there are many others like it. But each of us has his
prevailing and dominant emotions which constitute the habitual
attitude of his mind. And by the habitual indulgence of any emotion the
features will become habituated to the expression of it, and so the set
of our features comes at last to express our prevailing and dominant
emotions; in other words, our _character_.

[Illustration: THE NOSTRILS OF THE APTERYX ARE AT THE TIP OF ITS BEAK.]

But let us return to the evolution of the nose. In these days of
universal "Nature study" nobody need be told that the practice of
breathing through the nostrils was introduced by the