ral weeks, even though
they are repeatedly washed and dried. A drop of the liquid in the eyes
will cause blindness, and Indians are said not unfrequently to lose
their sight from this cause. Owing to this remarkable power of offence
the skunk is rarely attacked by other animals, and its black and white
fur, and the bushy white tail carried erect when disturbed, form the
danger-signals by which it is easily distinguished in the twilight or
moonlight from unprotected animals. Its consciousness that it needs only
to be seen to be avoided gives it that slowness of motion and
fearlessness of aspect which are, as we shall see, characteristic of
most creatures so protected.

_Warning Colours among Insects._

It is among insects that warning colours are best developed, and most
abundant. We all know how well marked and conspicuous are the colours
and forms of the stinging wasps and bees, no one of which in any part of
the world is known to be protectively coloured like the majority of
defenceless insects. Most of the great tribe of Malacoderms among
beetles are distasteful to insect-eating animals. Our red and black
Telephoridae, commonly called "soldiers and sailors," were found, by Mr.
Jenner Weir, to be refused by small birds. These and the allied
Lampyridae (the fireflies and glow-worms) in Nicaragua, were rejected by
Mr. Belt's tame monkey and by his fowls, though most other insects were
greedily eaten by them. The Coccinellidae or lady-birds are another
uneatable group, and their conspicuous and singularly spotted bodies
serve to distinguish them at a glance from all other beetles.

These uneatable insects are probably more numerous than is supposed,
although we already know immense numbers that are so protected. The most
remarkable are the three families of butterflies--Heliconidae, Danaidae,
and Acraeidae--comprising more than a thousand species, and
characteristic respectively of the three great tropical regions--South
America, Southern Asia, and Africa. All these butterflies have
peculiarities which serve to distinguish them from every other group in
their respective regions. They all have ample but rather weak wings, and
fly slowly; they are always very abundant; and they all have conspicuous
colours or markings, so distinct from those of other families that, in
conjunction with their peculiar outline and mode of flight, they can
usually be recognised at a glance. Other distinctive features are, that
their colou