hunter has had the experience of watching his expected game, when all of a
sudden it would start off with a nervous jerk, and without waiting to
sniff the air, as is usual, would bolt precipitately from the scene.
Moreover, many beasts of prey are known to sense the presence of their
natural prey, even when the wind is in the other direction, and there is
no sound or movement made by the crouching, fearstricken animal. Certain
birds seem to sense the presence of particular worms upon which they feed,
though the latter be buried several inches in the earth, or in the bark of
trees.

Savage man also has this faculty developed, as all travellers and
explorers well know. They are as keen as a wild animal to sense the
nearness of enemies, or, in some cases, the approach of man-eating beasts.
This does not mean that that these savages are more highly developed than
is civilized man--quite the reverse. This is the explanation: when man
became more civilized, and made himself more secure from his wild-beast
enemies, as well as from the sudden attacks of his human enemies, he began
to use this sense less and less. Finally, in the course of many
generations, it became almost atrophied from disuse, and ceased reporting
to the brain, or other nerve centres. Or, if you prefer viewing it from
another angle, it may be said that the nerve centres, and brain, began to
pay less and less attention to the reports of this sense (trusting more to
sight and hearing) until the consciousness failed to awaken to the
reports. You know how your consciousness will finally refuse to be
awakened by familiar sounds (such as the noise of machinery in the shop,
or ordinary noises in the house), although the ears receive the
sound-waves.

Well, this is the way in the case of this neglected sense--for the two
reasons just mentioned, the average person is almost unaware of its