116 NATURAL HISTORY OF 



diversified merely by the effects of chance, food, and 

 climate, though all of them reside together in the same 

 regions, such as India, and maintain their distinctions ; 

 or the species Canis alone, as now classified, must offer 

 the union of three or more, aboriginally different. This 

 is plainly indicated by the great inequality in the num- 

 ber of mammae ; for they are not always in pairs, and 

 vary from one individual to another, from five and six 

 to seven, eight, nine, and ten.* No condition of exis- 

 tence that we know of, can produce such an anatomical 

 irregularity, without a presumption, that it arises from 

 the intermixture of different types ; and the opinion is 

 further borne out, by other structural differences in 

 dogs, strictly so called, amounting to a greater diver- 

 sity of forms than there are between that species and 

 the wolf, dhole, or chakal ; differences which maintain 

 themselves, with very slight modifications, in the ex- 

 treme climates, whither Man has conveyed the various 

 races, large or small, and amounting, in some cases, 

 to greater hindrance to the continuation of so called 

 varieties, than are recorded to have obstructed the 

 experiment between wolf and dog already noticed. 



The Felidce offer another instance of blending two 

 or more species without apparent difficulty. The breeds 

 of the domestic cats produce with the wild species of 



* On the property of a relative, there was lately a bitch, 

 of the Spanish mastiff breed, twenty-nine inches at the 

 shoulder, who brought forth twelve puppies at one birth ; 

 indicating even a greater disturbance in the original spe- 

 cies, and proving, that mastiffs are by no means so sterile 

 as is pretended. 



