LAW OF HEREDITY 229 



have been possible with a slower bodily development and later 

 maturity. Thus we see the folly of attempting to force early laying 

 at the expense of other functions of the body. The aim should 

 be to give the bodily functions every incentive to healthy, normal 

 growth and maturity, after which time, with the strength and vital- 

 ity incident to strong functional activity, the greatest usefulness 

 of the individual can be expected. 



Laws of Breeding. — There are certain definite laws which 

 govern breeding, but in the science of breeding many principles 

 and interpretations either remain undiscovered or cannot in every 

 instance be explained. The purpose in the following sections will 

 be to outline some of the more fundamental laws, and assist the 

 student to such an understanding of the knowledge of to-day as 

 will enable him to pursue the art of breeding with a clearer insight 

 and with greater certaintj^ of success. 



Many of the laws or rules of breeding which have been expressed 

 scientifically during the last two hundred years had been previously 

 handed dc wnfrom generationto generation in traditional form. The 

 fact that early statistics were not kept in definite form militated 

 against the general diffusion of knowledge of results, and is partly re- 

 sponsible for the slow development made in the study and progress of 

 the science of breeding prior to the last two centuries. In recent 

 years more progress has been made and many principles established. 



Law of Heredity. — The law of heredity as usually stated is: 

 Like begets like. It implies that the characteristics of the parent 

 will appear in a more or less marked degree in the offspring, and 

 refers directly to the transmission of individual characteristics to 

 future generations. Heredity is too broad a term to apply merely 

 to one individual parent or offspring, but should include a group 

 of individuals which constitute the parentage, as well as a group 

 of offspring. The law of heredity and the principles for which it 

 stands are fundamental to all breeding operations. The poultry 

 breeder must become familiar with all that concerns preceding 

 generations in order properly to plan for and achieve results in 

 succeeding generations. The difficult problem confronting the 

 student is to determine or predict to what degree the progeny 

 will resemble the parent, since many factors are at work which 

 may cause variations from the type, and also produce entirely 

 new traits and characteristics. 



Practical Examples. — When applied to classes of poultry, the 

 law that " like begets like " finds ample illustration in the dis- 



