10 PRINCIPLES OF BREEDING 



in the ancient condition ; the whole life-history is not recapitu- 

 lated. But in the normal horse there is no arrest of develop- 

 ment. The recapitulation is carried out to its full extent, 

 though, in the later stages, in a reversed direction. . . . When, 

 therefore, we see an organ better developed in the embryo 

 than in the adult, we must conclude that reversed selection 

 has been at work. . . . There is on the average a greater 

 tendency towards reversion than towards progression, a 

 greater tendency to vary towards the ancestry than away 

 from it ... a greater tendency to let the last steps made in 

 the life-history lapse in the development than to add other 

 steps to them. . . . Two forces are constantly at work in 

 Nature Natural Selection and Reversion. The former 

 causes progressive evolution, the latter regressive evolution. 

 They are opposed, but one would be quite inadequate without 

 the other. They are warring forces, but their resultant is a 

 near approach to perfection." 



The force of inheritance is strongest in old and well- 

 established pure breeds, but even among the best a very 

 inferior animal (as the American " scally-wag " among cattle) 

 may appear at times. This degenerate specimen should 

 never be allowed to breed. It is by getting rid of all such 

 inferior or even moderately good animals that our breeds 

 are improved. " Fashionable pedigree " without the skilful 

 elimination of inferior specimens has in every instance led 

 to disaster, alike to the breed and to the breeders. Weeding, 

 or " artificial selection," acts much in the same way among 

 domesticated animals as the law of the " survival of the 

 fittest " does among wild ones. A well-bred, though plain- 

 looking bull, if he has no deformity, or no very objectionable 

 points, usually breeds much better and more uniform stock 

 than a handsome one without a pedigree. In selecting, it is 

 much more important to have the sires than the females 

 good, because strongly bred sires often get their best stock 

 from cows not bred in line, and one bad sire may affect a 

 large number of offspring, whereas an inferior female influ- 

 ences only her own young, which are comparatively limited 

 in number. The belief was entertained by Darwin, and 

 accepted universally for years after his death, that "the 

 influence of the first male by which a female produces young 

 may frequently be seen in her future offspring by different 

 sires." The evidence accepted in support of the assumption 



