INTRODUCTORY REMARKS. 7 



It is only upon this principle that we can account 

 for the different number of mammae which domestic 

 dogs are provided with ; for physiologists, we ap- 

 prehend, are not justified in assuming the difference 

 in organs of such importance to arise from domesti- 

 city, food, or climate : no other domestic animal is 

 thus found altered by these circumstances; and 

 even in the sow, should they be found to differ, it 

 is evident that more than one original species is in- 

 termixed. Now, of domestic dogs, Mr. Dauben- 

 ton examined twenty-one individuals of both sexes, 

 and found eight who had five on each side, making 

 ten ; eight with four on each side, making eight ; 

 two with five on one side and four on the other, 

 making nine; and three with four on one, and 

 three on the other, giving seven. We have seen 

 already, that the maximum of mammae in the 

 canines is ten, and the minimum six ; that in all 

 the wild species the number is always in pairs, and 

 that they never vary in a species. To w r hat other 

 cause, then, can we ascribe the anomaly in domes- 

 tic dogs so justly as to an intermixture of species ? 

 Nations, at first, reclaiming the best disposed canines 

 of their own woods, and after a gradual demorali- 

 zation by servitude, in animals by nature prurient, 

 succeeding in making cross breeds with the do- 

 mestic species of other tribes, derived from other 

 regions. This opinion is strengthened by the fact, 

 that the attractions to form a cross breed with 

 wilder animals, have always originated with the 

 domestic races. We may regret the celebrated 



