SPECIES AND VARIETIES. 641 



of Paris, in which dogs and wolves were united tog-ether, 

 and their progeny made to breed with one another ; but he 

 'draws the singular conclusion, that the progeny were hybrids, 

 and not the offspring of the same species, because the mixed 

 breed became deteriorated from generation to generation. 

 But the fact proves nothing with respect to the argument of 

 M. Cuvier, and is but one of innumerable examples of effects 

 long known in the practice of the breeders of domesticated 

 animals. Not only is the dog not exempt from the injury to 

 the constitution which results from continually reuniting 

 animals of the same family in blood, but he is peculiarly sus- 

 ceptible of deterioration from this cause. The experiment is 

 easily and quickly made. If we shall breed a pair of dogs from 

 a male and female of the same litter, and unite again the off- 

 spring of this pair, we shall produce at once a feeble race of 

 creatures ; and the process being repeated for one or two 

 generations inore, the family will die out, or be incapable of 

 propagating their race. A gentleman of Scotland made the 

 experiment on a large scale with certain fox-hounds, and he 

 found that the race actually became monstrous, and perished 

 utterly. We do not know the precise details of M. Cuvier's 

 experiment, but if it at all approached to that referred to 

 with respect to the nearness of blood of the animals united, 

 the result is no other than what might have been inferred 

 from old experience. Nay, the want of due exercise and 

 suitable treatment, would account for a decay of physical 

 strength in the animals subjected to the experiment. At 

 Moscow, we are informed, on the authority of Pallas, a mixed 

 breed was produced betw r een the Black Wolf and the Dog, 

 the descendants of which were fruitful with one another; 

 and 110 notice is taken of subsequent degeneracy. In truth, 

 there is not the least reason to believe, that a mixture of the 

 blood of the Wolf with that of the Dog would produce de- 

 scendants whose progeny would degenerate. Analogy rather 

 leads us to infer, that a mixture of the blood of the wilder 

 and stronger animal would add strength and vigour to the 



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