, launching them,
and then going aboard their little rafts. They then turn their heads to
the centre, and their tails, which hang in the water, are used as
paddles and rudders until they reach the destined shore.

Among travellers none are more famed than the camels. In their sphere
and use they are supreme, and Nature has prepared them especially for
travelling on the dry, hot, and barren deserts. They are truly the
"ships of the desert" for they travel on a sea of sand, and their
pad-like feet, so poorly adapted for travel on moist soil, is admirably
suited to the desert sands. They are capable of travelling many days
without food or water, and are used extensively in the desert regions of
the East not only as beasts of burden but for their milk, which is an
important article of diet in those countries where the camel is at home.

Animals that do not migrate, especially those living in cold climates,
change their clothing at regular intervals. Their hair or fur increases
in thickness in winter. If we compare the Indian and African elephants
of to-day, whose delicate thin hair is scarcely noticeable, with the
great extinct mammoth, which had an enormous amount of woolly fur, we
readily see the great difference in their clothing. Yet these animals
are members of the same great family. The same difference may be
noted with horses: the Arabian horse, for example, has short,
glistening fur, while those of Iceland and Norway have very thick fur;
the same is true of Northern and Southern sheep. Animals which live in
temperate regions, put on much thicker coats in winter, and shed them as
summer approaches.

[Illustration: _American Museum of Natural History, New York_

THE BLACK BEAR IS NOT ONE OF THE GREAT MIGRATING ANIMALS. THE THICKNESS
OF HIS COAT MUST THEREFORE CHANGE WITH THE SEASONS.]

[Illustration: _American Museum of Natural History, New York_

RABBITS SEEM TO HAVE A WELL-DEVISED SYSTEM IN THEIR ROAD-BUILDING,
RUNNING THEIR PATHS IN AND OUT OF UNDERBRUSH IN A TRULY INGENIOUS
MANNER.]

The love of their original homes is one of the most striking features of
certain animal travellers. The fierce struggle for existence and the
territory required for an animal's home largely determine the amount of
effort they make to seize and hold certain possessions. A pair of
wildcats, for example, require a comparatively small hunting ground. But
this they will defend against invasion even to the point of death. There
are