nevertheless I have been assured by Mr. Warwick, that one ran at the
Caledonian Champion meeting of April 1860, and was "marked precisely like a
black-and-tan terrier." This dog, or another exactly the same colour, ran
at the Scottish National Club on the 21st of March, 1865; and I hear from
Mr. C.M. Browne, that "there was no reason either on the sire or dam side
for the appearance of this unusual colour." Mr. Swinhoe at my request
looked at the dogs in China, at Amoy, and he soon noticed a brown dog with
yellow spots over the eyes. Colonel H. Smith (1/40. 'The Naturalist
Library' Dogs, volume 10 pages 4, 19.) figures the magnificent black
mastiff of Thibet with a tan-coloured stripe over the eyes, feet, and
chaps; and what is more singular, he figures the Alco, or native domestic
dog of Mexico, as black and white, with narrow tan-coloured rings round the
eyes; at the Exhibition of dogs in London, May 1863, a so-called forest dog
from North-West Mexico was shown, which had pale tan-coloured spots over
the eyes. The occurrence of these tan-coloured spots in dogs of such
extremely different breeds, living in various parts of the world, makes the
fact highly remarkable.

We shall hereafter see, especially in the chapter on Pigeons, that coloured
marks are strongly inherited, and that they often aid us in discovering the
primitive forms of our domestic races. Hence, if any wild canine species
had distinctly exhibited the tan-coloured spots over the eyes, it might
have been argued that this was the parent-form of nearly all our domestic
races. But after looking at many coloured plates, and through the whole
collection of skins in the British Museum, I can find no species thus
marked. It is no doubt possible that some extinct species was thus
coloured. On the other hand, in looking at the various species, there seems
to be a tolerably plain correlation between tan-coloured legs and face; and
less frequently between black legs and a black face; and this general rule
of colouring explains to a certain extent the above-given cases of