LINE BREEDING AND MENDEL'S LAW 187 



bred together till they bear a family likeness easily 

 noted, they may be properly called a "strain." The 

 Standard of Perfection calls it " a family bred in line." 

 " Atavism " is what poultrymen often call " throwing 

 back " or " jumping back." It is reversion to the traits 

 of ancestors, perhaps far back. 



One who has not thought much along these lines 

 needs first to grasp the fact of multiplicity of ancestors 

 behind each of his fowls. A certain pet of yours, 

 shall we say, had a father and a mother. So had the 

 father; so had the mother. Here are seven birds. 

 The four grandparents had each two immediate parents; 

 this makes fifteen. The eight great grandparents had 

 each two immediate parents, making sixteen more. The 

 next step back gives thirty-two more. Here, in four 

 steps backward, if there has been no close breeding, we 

 find sixty-two ancestors of your pet. In a smaller degree 

 it is the " melting pot " over again ; each fowl has an 

 infinite number of ancestors, and is the sum of the traits 

 of her ancestral family. But this family is a combina- 

 tion, it may be, of hundreds of families of thousands ! 

 Who shall say how many? Is it any wonder that you 

 cannot make the descendants of your pet what you will, 

 when you have to combat constantly characteristics 

 continually recurrent from the past, which to you now 

 seem faults? 



Line breeding, to put it into clear and common terms, 

 is simply an effort to give a fowl fewer ancestors. This 

 is done by breeding her to another which has at least 

 in part the same ancestors. Three results may be 

 counted on : (a) the intensifying of faults ; (b) the inten- 

 sifying of virtues ; (c) the lessening of vigor, unless 



