THE GENERAL ASPECTS OF ANIMAL BREEDING 447 



testify eloquently to the opportunity for improvement which exists in 

 the livestock breeding industry of the country. 



The Art of Breeding. As an inevitable result of the years of careful 

 management to which livestock has been subjected, there has grown up a 

 considerable fund of empirical knowledge having to do not only with the 

 best methods of caring for and feeding animals, but also with the best 

 methods of mating them to ensure the production of the proper type of 

 offspring. Many systems of breeding have been subjected to rigid 

 practical tests; tests which have been duplicated and reduplicated in 

 single breeds and in different breeds. Consequently, although many 

 mystical ideas have often survived over long periods and although 

 some still have their following among practical men, particularly if they 

 happen to have been championed by breeders of outstanding success, 

 nevertheless the tendency has been slowly, but surely, to separate the 

 true from the false. Animal breeding practice in its best form has 

 reached an exceedingly high state of development; the old herdsmen who 

 have grown up among their livestock, although their scientific training 

 may be very limited, are masters of the art of breeding. Like artists in 

 general they do not need to know very much about the composition of 

 the materials with which they work ; what they do need to know, and in 

 truth what some of them do know marvellously well, is how to utilize 

 the materials to the best advantage. 



The Problems of Animal Breeding. Here we may be permitted to 

 digress a moment in order to emphasize the fact that the problem facing 

 the animal breeder is different from the one facing the plant breeder. 

 There are many reasons for this fact some of which it may be well to state 

 here in order that no misunderstanding as to the general applicability 

 of the laws of variation and heredity may arise. In the first place in 

 plant breeding we are more particularly concerned with questions of 

 local adaptation and matters of kindred nature. Plants are notoriously 

 susceptible to differences in the environment because of their close re- 

 lationship to conditions of soil and climate. It is a familiar experience 

 to find that varieties of plants of proven worth in one locality fail miser- 

 ably to live up to their reputation in some different region. Now to a 

 certain extent this is true also of animals, but it must be patent to anyone 

 that livestock is on the whole relatively independent of environmental 

 influences. Man himself has migrated into new regions from the begin- 

 ning of time, usually taking his herds with him. Inclemencies in the new 

 surroundings have been met by construction of rude shelters or by seasonal 

 emigrations. In the present time the construction of suitable shelters 

 is, indeed, a universal practice, so that today domesticated animals ex- 

 hibit an independence from the environment almost as great as that of 

 man himself. As a consequence of the lesser need of considering envi- 



