4 THE DOG IN HEALTH. 



which was the chief occupation of primitive and uncivil- 

 ized men. 



That the dogs possessed by the aborigines of North 

 America bear a close resemblance to the various kinds 

 of wolves found wild in these regions is a matter of 

 frequent observation. It is further well known that the 

 dogs of the natives breed freely with wolves, and the 

 same remarks apply to some breeds of dogs of Europe 

 and other parts of the world. There is equally good evi- 

 dence to believe that some breeds of dogs are to be re- 

 ferred to the jackal. Upon the whole, it would seem prob- 

 able that " the domestic dogs of the world are descended 

 from two well-defined species of wolf (viz., Canis lupus 

 and Canis latrans\ and from two or three other doubt- 

 ful species (namely, the European, Indian, and North Af- 

 rican wolves) ; from at least one or two South American 

 canine species ; from several races or species of jackal ; 

 and perhaps from one or more extinct species " (Darwin). 



But this origin of the dog being only probable and 

 not demonstrable, we are entitled to ask whether it makes 

 the nature of the dog as we know it to-day more intelli- 

 gible than the theory that he is derived from some wild 

 forms long since extinct and of which we know little or 

 nothing. In other words, referring to our illustration, is 

 the greyhound more readily understood as a dog and as 

 a courser on this hypothesis of origin from some wild 

 forms now existing ? "Without going into details at this 

 time, we agree with those who think that without some 

 such theory the chain of natural connections can not be 

 forged, but that with it a flood of light is thrown on the 

 whole nature of the dog, even to his minutest traits and 



