distinct tints in all highly
coloured birds; the region of the furcula has often a distinct patch of
colour, as have the pectoral muscles, the uropygium or root of the tail,
and the under tail-coverts.[130]

Mr. Tylor was of opinion the primitive form of ornamentation consisted
of spots, the confluence of these in certain directions forming lines or
bands; and, these again, sometimes coalescing into blotches, or into
more or less uniform tints covering a large portion of the surface of
the body. The young lion and tiger are both spotted; and in the Java hog
(Sus vittatus) very young animals are banded, but have spots over the
shoulders and thighs. These spots run into stripes as the animal grows
older; then the stripes expand, and at last, meeting together, the adult
animal becomes of a uniform dark brown colour. So many of the species of
deer are spotted when young, that Darwin concludes the ancestral form,
from which all deer are derived, must have been spotted. Pigs and tapirs
are banded or spotted when young; an imported young specimen of Tapirus
Bairdi was covered with white spots in longitudinal rows, here and there
forming short stripes.[131] Even the horse, which Darwin supposes to be
descended from a striped animal, is often spotted, as in dappled horses;
and great numbers show a tendency to spottiness, especially on the
haunches.

Ocelli may also be developed from spots, or from bars, as pointed out by
Mr. Darwin. Spots are an ordinary form of marking in disease, and these
spots sometimes run together, forming blotches. There is evidence that
colour markings are in some way dependent on nerve distribution. In the
disease known as frontal herpes, an eruption occurs which corresponds
exactly to the distribution of the ophthalmic division of the fifth
cranial nerve, mapping out all its little branches even to the one which
goes to the tip of the nose. In a Hindoo suffering from herpes the
pigment was destroyed in the arm along the course of the ulnar nerve,
with its branches along both sides of one finger and the half of
another. In the leg the sciatic and scaphenous nerves were partly mapped
out, giving to the patient the appearance of an anatomical diagram.[132]

These facts are very interesting, because they help to explain the
general dependence of marking on structure which has been already
pointed out. For, as the nerves everywhere follow the muscles, and these
are attached to the various bones, we see h