GENERAL PRINCIPLES OF BREEDING. Ill 



generations. That fixity of type, however, is above all a charac- 

 teristic of those races which have been carefully selected and 

 bred up to a certain standard for many generations, so that in 

 our best, longest established and most esteemed breeds, we have 

 a legacy of the most valuable kind left us by the successful 

 breeders of the past, with which we may mould our inferior 

 races almost at will. 



8. That while breeding continuously from the nearest rela- 

 tions tends to a weakened constitution, the aggravation of any 

 taint of disease in the blood and sterility, yet that these may be 

 avoided by infusing at intervals fresh blood of the same family, 

 but which has been bred apart from this branch of it for several 

 generations. That, moreover, the highest excellence is some- 

 times only attainable by breeding very closely for a time. 



9. That diseased or mutilated animals are generally to be 

 discarded from breeding. That mutilations resulting in disease, 

 that disease existing during pregnancy, and disease with a con- 

 stitutional morbid taint, are above all to be dreaded as transmis- 

 sible. 



10. That there is some foundation for the opinion that the 

 sire tends to contribute more to the locomotion and external 

 organs, nerve and vigor, and the dam to the size and internal 

 organs, so that if we cannot obtain the greatest excellence in 

 both, we should, at least, seek to have each unexceptionable in 

 the parts and qualities attributed to it. 



11. That with regard to the controlling of the production 

 of sexes, while the Creator has made them at first male and 

 female, and will probably continue to do so irrespective of our 

 meddling, yet there is reason to believe that certain conditions 

 of the parents influence the sex of the progeny to a percep- 

 tible degree. If the feminine element in the progeny is in- 

 creased by rendering the system of the mother more soft, 

 lax, and adipose by high feeding and want of exercise, by the 

 strength and vigor of the female as compared with the male, 

 and perhaps even by having the females put to the male on the 

 earliest symptoms of heat ; and if the male element is increased 

 by the greater strength and vigor of the sire as compared with 

 the dam, and perhaps even by having the female served only 

 as the heat is passing oft', we need not despair of increasing at 

 will the number of females or males in our stock, but ordinary 



