72 ON THE REVOLUTIONS OF 



The small marks of tusks in the domestic pig, and the juncture of 

 the hoofs in some of this race, are the extreme difference that we have 

 produced in the herbivorous domestic kind. 



The most marked effects of the influence of man is evinced on the 

 animal over which he has obtained the most complete conquest — the 

 dog. This species is so much devoted to man, that even the very 

 individuals seem to have sacrificed themselves to us, with their 

 interests and their feelings. Conveyed by man to all parts of the uni- 

 everse, subjected to every cause capable of influencing their develope 

 ment, and joined in their union according to the taste of their masters, 

 dogs vary so much in colour ; in the thickness of their hair, which is 

 sometimes lost ; in their breed ; in height, which differs as one to five 

 in lineary dimensions, which makes more than an hundred fold in the 

 mass ; in the form of the ears, the nose, and the tail ; — as to the 

 relative length of their legs ; as to the progressive developement of 

 the brain in the domestic variety, whence even results the shape of 

 the head ; sometimes slender, with a sharp nose, and broad forehead ; 

 sometimes with a short nose and round forehead ; as these dif- 

 ferences are observable in a mastiff and a water spaniel in a 

 greyhound and a pug ; that these effects become more strongly 

 marked than in those of any wild species of a similar natural genus. 

 In fact, and this is the maximum of the difference known at the 

 present time in the animal kingdom, that there are breeds of dogs 

 which have an additional toe on the hind leg, with correspondent 

 bones of the tarsus, as there are in the human race some families 

 having six fingers on each hand. 



But in all these varieties the relations of the bones remain the 

 same, and the shape of the teeth never undergoes any palpable change ; 

 although there are some individuals which have an extra and false 

 grinder, sometimes on one side, and sometimes on the other *. 



There are then, in animals, characteristics which defy all influence, 

 whether natural or human, and there is nothing which proves to us 

 that time will effect any more than climate and a state of domestica- 

 tion. I know that some naturalists rely much on the thousands of 

 ages which they can accumulate with a stroke of the pen ; but in 

 such matters we can only judge of what length of time would produce, 

 by multiplying in thought what the least time will effect. I have 

 endeavoured to collect the most ancient documents of the forms of 

 animals, and there are no countries which furnish us with older and 



* See my brother's (M. Frederic Cuvier's) Memoir on the varieties of dogs, inserted 

 in his ' Annales du Museum d'Histoire Naturelle.' This work was done at my 

 request from the skeletons of all varieties of dogs, expressly prepared. 



