his is
why he has been chosen! If an enemy appears, or any form of danger is
approached, they carry on an immense amount of chattering and proceed
only when they have talked it out. Any hunter that should be foolish
enough to attack them, unless he were already up a tree, would be torn
to pieces with their terrible teeth and tusks. They are as bloodthirsty
as the wild boars of the Black Forest of Germany, and will sometimes
actually tear down a tree up which an enemy has escaped, that they may
kill him.

The African apes have an interesting way of sending their sentinel to
the top of an adjacent rock or tree, that he may look over the
surrounding valleys and plantations before they go to plunder a garden
or field. If he sees any danger, he utters a loud shriek, and the entire
troop immediately runs away. The monkeys of Brazil post a guard while
they sleep; the same is true of the chamois and other species of wild
antelope.

A few years ago, many of the sheep in the northern part of Wales had
become quite wild, and they usually grazed in parties of twelve to
twenty, always having a sentinel so stationed as to command a prominent
view of the surrounding territory. If any animal or person came near, he
would give a peculiar hiss or whistle, repeating it two or three times,
at which the whole herd would scamper away to places of safety.

One of the most striking facts about migration is its never-failing
regularity and success. Most animals migrate at the recurrence of the
breeding season. Of these, the great sea-turtle, which seeks the shallow
water and deep sandy hills when ready to lay her eggs, is well known.
Notwithstanding the great risks that practically all travelling animals
assume, they are successful as a whole in their travels, and many return
to bear testimony to a successful trip even across continents and
sometimes the ocean. They migrate, for a variety of reasons. When it is
not for a more desirable climate, nor more food, nor even better
breeding grounds, we must either believe it is because of the natural
desire to travel, or frankly admit that we do not understand it.

The Icelandic mice have probably the most curious methods of travelling
of all migratory animals. Dr. Henderson, an authority on Iceland, not
only verifies the fact himself, but gives the names of many prominent
investigators who have seen the mice crossing small rivers and streams
on thin pieces of dry board, dragging them to the water