BREEDING SYSTEMS 251 
If the purpose is breed improvement, using as a basis family 
lines already established, then line breeding and, to some extent, 
inbreeding should be followed. When new types or breeds are 
desired, two courses are open,—either to watch for and fix mutations 
or sports as they occur, or, more often, to accelerate possible varia- 
tions by crossing, and then from the hybrid progeny attempt to 
develop desired characters. But Mendel has shown this to be a 
difficult and tedious proposition at the best, and impracticable on 
the average poultry farm. 
If the purpose is to improve common stock at small expense, 
then grading up is the best method. In all cases the idea should 
be to breed from the best of the fowls which have the desired trait 
developed to the highest degree of perfection. 
Selection.—Regardless of the extent or the method of breeding, 
the poultryman has always at command the power of selection, 
and it is the real source of improvement. It is made possible by 
variation, and is responsible for many of the most noted develop- 
ments in poultry breeding. 
By selection is meant the ability to choose stock for propagating 
purposes which possess desirable qualities, and which are prepotent 
with regard to these characteristics, so that, with proper care, 
the resulting progeny will be of a high standard of excellence 
which can be maintained. To select consistently and bring about 
definite improvement, a breeder must have a clear idea of his 
purpose, and work continuously toward it. He must know the 
breed with which he is working as well as its ancestry, must under- 
stand the principles underlying selection, and use judgment in 
departing from certain well-defined lines when compelled thereto 
for economic or commercial reasons. 
In selection there is the important fundamental advantage 
that it results in absolute improvement of quality, and not merely 
in the elevation of the flock to a higher standard by the elimination 
of the lower or average members. It accomplishes two well- 
defined results: (1) It increases the production of individuals, 
thereby making it possible to secure increasingly higher individual 
records; and (2) it stimulates the average production by raising 
the average of the mass, by eliminating the poor producers, and 
by substituting heavier layers in their place. 
Selection should be continuously practised, not only in the 
breeding pen, but in the elimination of weak or sick birds through- 
out the entire brooding and growing period. Fowls which show, 
