62 Milk and Its Products 
zonditions of environment, which, so far as the ordi- 
nary dairy herd is concerned, means simply more 
food; and that it was perpetuated in the case of pure- 
bred animals by selection. Having obtained improve- 
ment now by the use of a pure-bred male on com- 
mon or mixed females, it is, of course, necessary 
that it shall be maintained by liberal care and 
feeding. A pure-bred animal can transmit only its 
inherited ‘tendencies, and if these inherited tendencies 
are not backed up by abundant and nutritious food, 
the improvement secured is sure to be lost. Having 
now secured a marked improvement in two or three 
generations by the use of a pure-bred male on com- 
mon or mixed females, with intelligent selection and 
intelligent inbreeding, the further course of improve- 
ment is the maintenance of proper conditions of 
environment and careful selection. As generations 
come on, characteristics of the original pure-bred sire 
will become more and more fixed and uniform, rever- 
sions will be less and less frequent, and the herd will 
be practically pure-bred from the standpoint of the 
capacity of individual members to reproduce their 
characteristics, though they never become eligible to 
registration in the herd book. This is a course that 
has been successfully practiced in the improvement of 
a large number of herds of dairy animals, and is 
entirely within the reach of anyone of ordinary skill 
and intelligence. 
Major and minor dairy breeds.—The breeds of dairy 
cattle have been developed in the main in localities 
where, for one reason or another, a dairy industry 
