f which we know nothing; and since they are not found in
present-day animals with unpleasant qualities, they are not, strictly
speaking, warning colours.

Desert animals are in most cases desert-coloured. The lion, for example,
is almost invisible when crouched among the rocks and streams of the
African wastes. Antelopes are tinted like the landscape over which they
roam, while the camel seems actually to blend with the desert sands. The
kangaroos of Australia at a little distance seem to disappear into the
soil of their respective localities, while the cat of the Pampas
accurately reflects his surroundings in his fur.

The tiger is made so invisible by his wonderful colour that, when he
crouches in the bright sunlight amid the tall brown grass, it is almost
impossible to see him. But the zebra and the giraffe are the kings of
all camouflagers! So deceptive are the large blotch-spots of the giraffe
and his weird head and horns, like scrubby limbs, that his concealment
is perfect. Even the cleverest natives often mistake a herd of giraffes
for a clump of trees. The camouflage of zebras is equally deceptive.
Drummond says that he once found himself in a forest, looking at what he
thought to be a lone zebra, when to his astonishment he suddenly
realised that he was facing an entire herd which were invisible until
they became frightened and moved. Evidently the zebra is well aware that
the black-and-white stripes of his coat take away the sense of solid
body, and that the two colours blend into a light gray, and thus at
close range the effect is that of rays of sunlight passing through
bushes.

The arctic animals, with few exceptions, are remarkable for imitating
their surroundings; their colour of white blends perfectly with the snow
around them. The polar bear is the only white bear, and his home is
always among the snow and ice. The arctic fox, alpine hare, and ermine
change to white in winter only, because during the other seasons white
would be too conspicuous. The American arctic hare is always white
because he always lives among the white expanses of the Far North. Both
foxes and stoats are carnivorous and feed upon ptarmigan and hares, and
they must be protectively coloured that they may catch their prey. On
the other hand, Nature aids the prey by providing them with colours that
enable them to escape the attention of their enemies.

The young of many of the arctic animals are covered with fluffy white
hair, so