THE PEDIGREE OF THE DOG 199 
First of all we may dismiss the rare South American 
bush-dog (Speothos), which is a small somewhat fox-like 
creature with a short tail and teeth of a quite peculiar 
type. Equally far removed from the line are the long- 
eared Cape fox (Ofocyon) and the African hunting-dog 
(Zycaon), the former having more teeth than the domes- 
ticated breeds, while the latter has fewer toes. Next we 
may eliminate the wild dogs of Asia, which are frequently 
separated from the other members of the family under 
the name of Cyon, as all these have one pair less of 
cheek-teeth in the lower jaw, and therefore obviously can- 
not be the ancestral stock, as an organ once lost cannot 
be replaced. Rather nearer to the domesticated races are 
the foxes and fennecs (Vulpes), exclusive of the South 
American species commonly so called. But if we examine 
the skull of the British or any other species of true fox, 
an important difference will be found between it and the 
skull of any domesticated dog, wolf, or jackal. This 
difference is best displayed in the shape of the projecting 
process of bone forming the hinder border of the socket of 
the eye; this process in a fox being distinctly concave, 
whereas in all the others it is highly convex. 
We thus arrive at the conclusion that the only existing 
members of the family that can possibly be the ancestors 
of the domesticated breeds are wolves, jackals, the Aus- 
tralian dingo, and certain South American species which, 
although commonly termed foxes, are really more closely 
allied to the jackals and wolves; and it is further obvious 
that the only extinct species which can claim a place in the 
line of descent are those having skulls and teeth of the 
wolf type—in other words, species of the genus Canis in 
its restricted sense. 
Before proceeding farther, it may be mentioned in con- 
