by the Study of Domestic Animals. 193 



varieties transmitting themselves liereditarily in the humanfamily. 

 Residing in every clime, and almost under every degree of tem- 

 perature, changing in a thousand ways the quality and thequan- 

 tity of his food, and following the most different kinds of occu- 

 pation, he presents in the multiplicity of his races and subraces, 

 and we might add, of his innumerable individual varieties, the 

 natural and necessary effect of the multiplicity of the causes 

 which operate upon him, and have for so long a period exerted 

 all their influence. 



Thus it happens, on the one hand, that among wild animals, 

 we find the causes of variation restrained within very narrow 

 limits, and consequently the varieties but few and not well 

 marked ; on the other hand, among domestic animals, and in 

 man, who in this point of view must be assimilated with them, 

 there are many causes, and consequently many manifestations of 

 variation, whose limits, both in number and power, can scarcely 

 be traced. But if, in this respect, there exists this vast differ- 

 ence between these two classes, it is easy to see that the state of 

 civilization in man, and the domestic condition which so exactly 

 corresponds to it among animals, have not really created a new 

 order of causes and effects, but have only multiplied, augmented, 

 and varied in detail the causes and effects which already existed 

 among wild beasts. In both, the modifying influences are always 

 the local circumstances, and more especially the habitat, the 

 kind of life, and food ; and the effects of the variations, first as 

 it respects the size and the colour, and then the proportion and 

 form of the organs ; a double resemblance which I might trace 

 into very minute details, and of which I might supply long and 

 accurate, and at the same time rigorous demonstrations, if the 

 preceding remarks,and the evident confirmation they receive from 

 a variety of well known facts, did not render it unnecessary. 



The benefit which may be deduced from these considerations 

 in the promotion of the special objects of this treatise is, as we 

 shall presently see, both direct and important. If the physical 

 variations which are produced in man by the influence of hi5 

 civilization were phenomena of a peculiar kind, and if the human 

 race were found in this, as in so many other respects, to be be- 

 yond the range of the lower creation, it is clear that, in the 

 study of the human races, we should be reduced to the neces- 



VOL. XXIXI. NO. XLV. JULY 1837. N 



