occasionally dappled (2/32. I state this from my own observations made
during several years on the colours of horses. I have seen cream-coloured,
light-dun and mouse-dun horses dappled, which I mention because it has been
stated (Martin 'History of the Horse' page 134) that duns are never
dappled. Martin (page 205) refers to dappled asses. In the 'Farrier'
(London 1828 pages 453, 455) there are some good remarks on the dappling of
horses; and likewise in Col. Hamilton Smith on 'The Horse.'), in the same
manner as is so conspicuous with grey horses. This fact does not throw any
clear light on the colouring of the aboriginal horse, but is a case of
analogous variation, for even asses are sometimes dappled, and I have seen,
in the British Museum, a hybrid from the ass and zebra dappled on its
hinder quarters. By the expression analogous variation (and it is one that
I shall often have occasion to use) I mean a variation occurring in a
species or variety which resembles a normal character in another and
distinct species or variety. Analogous variations may arise, as will be
explained in a future chapter, from two or more forms with a similar
constitution having been exposed to similar conditions,--or from one of two
forms having reacquired through reversion a character inherited by the
other form from their common progenitor,--or from both forms having
reverted to the same ancestral character. We shall immediately see that
horses occasionally exhibit a tendency to become striped over a large part
of their bodies; and as we know that in the varieties of the domestic cat
and in several feline species stripes readily pass into spots and cloudy
marks--even the cubs of the uniformly-coloured lion being spotted with dark
marks on a lighter ground--we may suspect that the dappling of the horse,
which has been noticed by some authors with surprise, is a modification or
vestige of a tendency to become striped.

(FIGURE 1. DUN DEVONSHIRE PONY, with shoulder, spinal, and leg stripes.)