CANIDA SSE 
The origin of the Domestic Dog, with its numerous breeds, 
has been, the subject of much controversy. Some naturalists 
believe it to be a distinct species, descended from one that no 
longer exists in a wild state; others have sought to find its pro- 
genitors in some one of the wild or feral races, either of true Dogs, 
Wolves, or Jackals; while others again believe that it is derived 
from the mingling of two or more wild species or races. It 
was probably the earliest animal domesticated by man, and few if 
any other species have undergone such an extraordinary amount of 
variation in size, form, and proportion of limbs, ears, and tail— 
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Fic. 252.—The Jackal (Canis aureus). 
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variations which have been perpetuated and increased by careful 
selective breeding. The Dingo or Australian Dog is met with wild, 
and also as the domestic companion of the aboriginal people. Dogs 
were also in the possession of the natives of New Zealand and other 
islands of the Pacific, where no placental mammals exist naturally, 
on their discovery by Europeans in the last century. 
The second group includes the wild Dogs of the south-east of 
Asia, described as Cyon, and distinguished by slight modifications 
as C. rutilans, C. dukhunensis, and C. javanicus, and differing from 
the above in wanting the small last lower tubercular molar. This 
difference reduces the number of the teeth to the same as in 
Viverra, and is precisely paralleled by some of the species of the 
extinct genus Cynodictis mentioned below. The muzzle is shorter 
