EFFECTS OF INBREEDING 



distinctly bad. Existing legislation against 

 the marriage of near-of-Mn is, therefore, on 

 the whole, biologically justified. On the other 

 hand, continual crossing only tends to hide 

 inherent defects, not to exterminate them; and 

 inbreeding only tends to bring them to the 

 surface, not to create them. We may not, 

 therefore, lightly ascribe to inbreeding or in- 

 termarriage the creation of bad racial traits, 

 but only their manifestation. Further, any 

 racial stock which maintains a high standard 

 of excellence under inbreeding is certainly one 

 of great vigor, and free from inherent defects. 

 The animal breeder is therefore amply jus- 

 tified in doing what human society at present 

 is probably not warranted in doing, viz. in 

 practicing close inbreeding in building up 

 families of superior excellence and then keep- 

 ing these pure, while using them in crosses 

 with other stocks. For an animal of such a 

 superior race should have only vigorous, strong 

 offspring if mated with a healthy individual 

 of any family whatever, within the same spe- 

 cies. For this reason the production of 

 " thoroughbred ' : animals and their use in 



151 



