Breeding and Rearing 53 
blood lines, and to fix the type or to improve the 
type there must he a certain amount of in-breeding. 
The objections that some harbor to this form of 
scientific selection have been proven today as ground¬ 
less, such as loss of virility and constitutional vigor. 
The best bred animals today are in-bred. The 
general formula is to breed with a common an¬ 
cestor on both sides, for instance, a common grand- 
sire, though there can be different arrangements, 
such as a common ancestor of the sire and the grand 
dam’s sire. 
Line breeding is a distinct form of in-breeding in 
that the breeding is entirely confined on one side to a 
certain family. If the results from such a family 
have proven themselves, it is conducive of very fine 
results and a benefit to the breed, since it tends to 
establish the potency of the individuals of this line, 
a much sought for quality among the breeders. 
Should any other result, though, make itself mani¬ 
fest, it should be immediately abandoned, for it will 
fix a fault with a greater tenacity than a virtue. 
The most concentrated form of breeding is In¬ 
tense-Breeding, that is, the direct breeding of sire 
to daughter or son to his dam, and while this has 
been necessary in the establishment of the breed, it 
must not be attempted with impunity by any one, 
unless he is a breeder of many, many years of experi¬ 
ence, with not only an absolute understanding of its 
requirements, but also with a perfect knowledge of 
breeding history of both families involved, otherwise 
such a breeding can .work immeasurable harm to the 
breed. 
