om gilded surfaces produced pupae with a brilliant golden
lustre; and the explanation is supposed to be that mica abounded in the
original habitat of the species, and that the pupae thus obtained
protection when suspended against micaceous rock. Looking, however, at
the wide range of the species and the comparatively limited area in
which micaceous rocks occur, this seems a rather improbable explanation,
and the occurrence of this metallic appearance is still a difficulty. It
does not, however, commonly occur in this country in a natural state.

The two classes of variable colouring here discussed are evidently
exceptional, and can have little if any relation to the colours of those
more active creatures which are continually changing their position with
regard to surrounding objects, and whose colours and markings are nearly
constant throughout the life of the individual, and (with the exception
of sexual differences) in all the individuals of the species. We will
now briefly pass in review the various characteristics and uses of the
colours which more generally prevail in nature; and having already
discussed those protective colours which serve to harmonise animals with
their general environment, we have to consider only those cases in which
the colour resemblance is more local or special in its character.

_Special or Local Colour Adaptations._

This form of colour adaptation is generally manifested by markings
rather than by colour alone, and is extremely prevalent both among
insects and vertebrates, so that we shall be able to notice only a few
illustrative cases. Among our native birds we have the snipe and
woodcock, whose markings and tints strikingly accord with the dead marsh
vegetation among which they live; the ptarmigan in its summer dress is
mottled and tinted exactly like the lichens which cover the stones of
the higher mountains; while young unfledged plovers are spotted so as
exactly to resemble the beach pebbles among which they crouch for
protection, as beautifully exhibited in one of the cases of British
birds in the Natural History Museum at South Kensington.

In mammalia, we notice the frequency of rounded spots on forest or tree
haunting animals of large size, as the forest deer and the forest cats;
while those that frequent reedy or grassy places are striped vertically,
as the marsh antelopes and the tiger. I had long been of opinion that
the brilliant yellow and black stripes of the tiger wer