2Q2 NATURAL HISTORY. 



tribes of men, this selection is no doubt carried on un- 

 consciously, but among the breeders of cattle, or among 

 pigeon-fanciers, it is a strictly scientific process, carried on 

 consciously and deliberately, and according to rules, which 

 are none the less fixed that they are largely 'rules of 

 thumb,' 



Those who wish to understand this most interesting 

 subject in all its bearings must turn to the pages of the 

 1 Origin of Species,' where it is fully treated by the hand of 

 the master. All that need be done here is to say one 

 word as to the relation between the known facts of ' artificial 

 selection ' on the one hand and the theory of the origin of 

 wild species by ' natural selection' on the other hand. 

 If it be admitted, namely, that our numerous varieties of 

 domesticated animals owe their peculiarities to the 

 * selection' exercised by man during the comparatively 

 brief period during which he has existed upon the earth, 

 it is not unreasonable to suppose that ' natural selection,' 

 operating through an infinitely longer period, and by 

 methods much more subtle and far-reaching, has produced 

 the different wild ' species ' of animals by modifications of 

 one or more aboriginal types. The unquestionable facts, 

 therefore, as to the production of our domesticated breeds 

 of animals from wild species by means of 'artificial 

 selection,' afford a strong presumption in favour of the 

 theory that our existing wild species have been produced 

 by the modification of pre-existing wild species through 

 the operation of 'natural selection.' 



