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 certainty 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 wn from generation to generationin 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 slowdevelopment 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- 
t 
