NATURAL HISTORY OF THE DOG. 33 



supplied by deriving the larger tribes, as the mastiff, &c. from the 

 hyena, and the terrier from the fox. 



As regards the identity of the dog with the jackal, there can, 

 I think, be but one opinion, when we consider the circumstances 

 of the limited geographical distribution of the latter animal. It 

 is well known that he is formed for warm regions only : in the 

 colder he never multiplies, wuth all the care man can bestow on 

 him ; and near the tropics no art can keep him alive. He is 

 physically designed for a high temperature, and cannot be natu- 

 ralized by art, like many other animals, to a cold one : it would 

 be most irrational, therefore, to suppose that he would be chosen 

 as the progenitor of an animal so widely diffused, north, east, west, 

 and south, as the dog. The dog, therefore, may lay claim to a 

 true originality of general character. But whether some of his 

 endless varieties may or may not have arisen from his own in- 

 termixture with nearly allied species, my limits will not allow me 

 to inquire further. 



Both sacred and prophane history have united in deriving man 

 from Asia, where we also find some of the most valuable of his 

 domesticated animals, as goats, sheep, dogs, &c., still existing 

 in their primeval state. If man, therefore, found the means of 

 transporting himself over the face of the globe, it may be sup- 

 posed he would be accompanied by these his dependents ; and if 

 man himself owes his variations from what must have been his 

 original type to the interventions of climate, diversifications of 

 food, and altered habits, it is most rational to suppose similar 

 alterations might take place in the animals he fostered. But it 

 might be expected, as it is found to have happened, that among them 

 the varieties of form, colour, and properties, would be more nume- 

 rous and remarkable ; because, in addition to the effects of climate, 

 man assumed the direction of all their energies, the selection of 

 their food, and the regulation of their sexual intercourse. Even 

 climate alone is equal to produce wonderful changes on animal 

 bodies. In ourselves it begets the extremes of white and black in 

 the colour of our skins within the tropics ; while extra-tropical 



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