One notable difference between man and the four-footed animals which
has often occurred to me is in the eye, and the greater perfection, or
rather supremacy, of the sense of sight in the human species. All
the animals--the dog, the fox, the wolf, the deer, the cow, the
horse--depend mainly upon the senses of hearing and smell. Almost their
entire powers of discrimination are confined to these two senses. The
dog picks his master out of the crowd by smell, and the cow her calf out
of the herd. Sight is only partial recognition. The question can only
be settled beyond all doubt by the aid of the nose. The fox, alert and
cunning as he is, will pass within a few yards of the hunter and not
know him from a stump. A squirrel will run across your lap, and a marmot
between your feet, if you are motionless. When a herd of cattle see a
strange object, they are not satisfied till each one has sniffed it; and
the horse is cured of his fright at the robe, or the meal-bag, or other
object, as soon as he can be induced to smell it. There is a great deal
of speculation in the eye of an animal, but very little science. Then
you cannot catch an animal's eye; he looks at you, but not into your
eye. The dog directs his gaze toward your face, but, for aught you can
tell, it centres upon your mouth or nose. The same with your horse or
cow. Their eye is vague and indefinite.
Not so with the birds. The bird has the human eye in its clearness, its
power, and its supremacy over the other senses. How acute their sense
of smell may be is uncertain; their hearing is sharp enough, but their
vision is the most remarkable. A crow or a hawk, or any of the larger
birds, will not mistake you for a stump or a rock, stand you never so
still amid the bushes. But they cannot separate you from your horse or
team. A hawk reads a man on horseback as one animal, and reads it as a
horse. None of the sharp-scented animals could be thus deceived.
The bird has man's brain also in its size. The brain of a song-bird is
even much larger in proportion than that of the greatest human monarch,
and its life is correspondingly intense and high-strung. But the bird's
eye is superficial. It is on the outside of his head. It is round, that
it may take in a full circle at a glance.
All the quadrupeds emphasize their direct forward gaze by a
corresponding movement of the ears, as if to supplement and aid one
sense with another. But man's eye seldom needs the confirmation of
his ear, while it is so set, and his head so poised, that his look is
forcible and pointed without being thus seconded.