FUNDAMENTAL PRINCIPLES 225 



Fundamental Principles. As a science, breeding is both com- 

 plex and varied. This is in part due to the obscurity surrounding 

 many of the phenomena, and to the great degree of variation in 

 results obtained under apparently the same conditions, also in part 

 to the influence which the purity of the individual exerts, as shown 

 in the results of future transmission. 



Fortunately, however, the fundamental principles of the science 

 of breeding, the complete understanding of which is essential to 

 success in practical breeding, are few in number, and readily under- 

 stood. These principles are as follows : 



1. Decide upon a standard of excellence, which may be either 

 real or imaginary, and always breed toward it. 



2. Always breed from parents both of whom conform as closely 

 as possible to this standard. 



3. Always breed from parents which are as purely bred as it 

 is possible to obtain them, that is, birds which have long been 

 bred without the addition of alien blood. 



4. Study the individuals, and endeavor to mate them so that 

 the faults of the parents will be corrected in the offspring. 



5. Practise a rigorous selection from hatching time to maturity, 

 and especially when mating the breeding hens. 



6. Always consider environment, such as housing and feeding 

 conditions. 



Breeding toward a standard of excellence gives the breeder a 

 guide by means of which he can frequently estimate his progress. 

 By following this guide without deviation definite results may be 

 much more quickly attained. The standard may be written or it 

 may be carried in the mind of the one engaged in breeding. In 

 the former case, one prepared by an association is generally used. 

 At the present time the American Poultry Association publishes 

 the " American Standard of Perfection," in which are given the 

 requirements of all standard-bred poultry. In the absence of this 

 standard the high excellence and uniformity now attained, as seen 

 at the large poultry shows, would be impossible. 



The necessity -of breeding only from parents which conform as 

 nearly as possible to the standard is based on the law of heredity 

 that like produces like, and that, in order to secure a given progeny, 

 the more nearly the parents conform to the standard the greater 

 are the chances that the offspring will develop the desired qualities. 



The study of .the science of breeding has shown that with an 

 increased admixture of alien or foreign blood there is always a pro- 



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