catus_
has the peculiar black bands divided into divisions of three by narrow
yellow rings, thus exactly mimicking a harmless snake, the _pliocerus
elapoides_, both of which live in Mexico. Presumably, the deadly variety
assumes the colouring of the harmless kind in order to deceive intended
victims as to his ferocity.

Surely this is sufficient evidence that colouration and pattern-design
is a useful camouflage device of the great struggle for existence. And
it is safe to assert that any animal that has enemies and still does not
resort to protective colouration or mimicry in some form is entirely
able to protect itself either by its size, strength, ferocity, or by
resorting to safety in numbers. Elephants and rhinoceroses, for example,
are too powerful to be molested when grown, except in the rarest cases,
and are furthermore thoroughly capable of protecting their young.
Hippopotamuses are protected by their immense heads, and are capable of
defending their young from crocodiles even when in the water.

The bison and buffalo, which were once so powerful on the plains of
North America, were protected by their gregarious habits, which
terrorised their enemies--the wolves. Their nurseries were a feature of
their wisdom. These were circular pens where the tall grass was tramped
down by expectant mothers for the protection of their young. This
natural nursery was protected from the inside by sentinels who went
round and round the pen constantly guarding the young not only from the
attack of wolves but also from venturing forth alone too early into the
open unprotected plains. In a similar way the snow-pens of the moose of
the Far North serve to protect them from the hungry hordes of wolves of
which they live in constant danger. This indicates that the annihilation
of the bison and buffalo was due, not to lack of wisdom, but to man's
inhumanity; for, taking advantage of their nurseries, the men crouched
near and concealing themselves in the grass killed not only the mothers
for food but even the young in their savage sport.

The large majority of monkeys are protectively coloured with some shade
of brown or grey, with specially marked faces. Entire packs of
Ceylonese species will, at the slightest alarm, become invisible by
crouching on a palm-tree. One of the most strikingly coloured African
monkeys is jet black with a white bushy tail, and a face surrounded by a
white ring, or mantle of long silky hair. He thus simulate