154 CARNIVORA FISSIPEDIA. 



Civilized nations have acquired many breeds of dogs 

 by " direct importation, and other varieties have been 

 secured by crossing and artificial selection, but some 

 strains have been introduced into countries, where they 

 were before unknown, by savage and half-civilized 

 people, who in their migrations have carried with them 

 the breeds they had obtained by domesticating the wolves 

 and the wild dogs of their native country. 



All the living representatives of the Dog family, in 

 which are included the Dogs, Foxes and Wolves, are so 

 much alike, and resemble one another so much in struc- 

 ture, habits and distinguishing characteristics, that scien- 

 tists have placed nearly all the species in a single genus. 

 Canis. The teeth of the dogs are much less carnivorous 

 in character than those of the cats, and their legs are 

 larger and more free from the body so they can walk 

 erect upon their limbs, and are adapted for running 

 rather than springing or climbing; as a rule they have 

 five toes upon the fore and four upon the hind feet, the 

 development of the rudiamentary fifth toe showing con- 

 siderable variation in the different species. The claws 

 in time become worn and blunt at the top because they 

 do not have the slightest power of retraction. The inner 

 toe of the fore feet is placed high up, and in some cases 

 is lacking. The normal number of teeth is forty-two 

 but one or two species have an extra molar on both sides 

 of each jaw, and a few have less than the normal number. 

 There is a remarkable resemblance in the sectorial teeth 

 of all the species, the Azara's Dog (Canis-jubata) of South 

 America, and the Raccoon Dog (Canis-procyonoides) of 

 Japan, who live largely on fruits and roots, having the 

 same pattern of sectorial teeth as the more carnivorous 

 forms. 



The difficulty of classifying the Canidae is increased 

 by the great range of variation in each species; but 

 apart from some structural peculiarities the foxes can 

 be distinguished from the dogs and wolves by their 

 bushy tails, elongated pupils, erect acute ears, and longer 

 muzzles. The skulls of the largest grey and red foxes 

 are inferior to that of the average Jackal, and those of 

 the smaller species of Foxes are less than half the length 

 of an average Wolf skull. 



