ur of the feet and the eye-spots are in some way correlated. I have
noticed, in various breeds, every gradation, from the whole face being
tan-coloured, to a complete ring round the eyes, to a minute spot over
the inner and upper corners. The spots occur in various sub-breeds of
terriers and spaniels; in setters; in hounds of various kinds,
including the turnspit-like German badger-hound; in shepherd dogs; in a
mongrel, of which neither parent had the spots; in one pure bulldog,
though the spots were in this case almost white; and in
greyhounds,--but true black-and-tan greyhounds are excessively rare;
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." 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[43] figures the magnificent black
mastiff of Thibet with a {29} 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 t