ANIMAL BREEDING 655 



3. The characters to be selected and bred for are generally 

 not few but many, and difficulties in selection necessarily increase 

 out of all proportion to the number of points to be attained. 



4. As if the breeder did not have troubles enough of his own, 

 fashion is. continually adding points that demand his attention 

 most imperiously, even at the expense of better things. 



5. Animals propagate but slowly, and breeding operations 

 necessarily extend over many years and several generations ; the 

 population cannot, therefore, be spread out to view, and there is 

 more or less uncertainty as to actual family history and individ- 

 ual merit, all of which makes selection more or less difficult 

 and uncertain. 



6. The young of most animals are promising, but selection 

 cannot safely be made at extreme immaturity, for the differ- 

 ences between inferiority and superiority are brought out only in 

 the development that comes with full maturity. The excellence of 

 breeding is mainly shown in the capacity for development, and 

 this cannot be foretold except as it may be predicted by a 

 general knowledge of the particular family line and the spe- 

 cial blood combination involved. Some of the most promising 

 "young things" are the bitterest disappointment. 



7. Animals are difficult of development, and many of the 

 best-bred things are never properly developed. 



8. Animals do not reproduce asexually, and their successful 

 production is conditioned upon high sexual fertility. Now, imper- 

 fect sexual development is one of the most common, if not the 

 most common, defect in both plants and animals. Plants may be 

 propagated by buds or cuttings, but animals are at the mercy of 

 sexual reproduction. In nature the existing lines are kept at 

 least fairly fertile by natural selection, but in domestication no 

 such controlling influence exists unless supplied by the breeder 

 himself. This lack he must provide for if he hopes to succeed, 

 but it constitutes one of his principal difficulties. 



9. Fashion and custom decree that animals shown at the fairs 

 shall be put into extreme condition, and this is a constant menace 

 to the efficiency of a breeding herd. 



10. A strong vein of speculation has entered into many lines 

 of animal breeding, the tendency of which is to unsettle prices 



