ANIMAL BREEDING 95 



called conception. At this time the future of the new animal 

 is determined. It has inherited all it can and henceforth only 

 gets nourishment from the dam. This new individual has 

 inherited the right to be something similar to its ancestors, 

 or to be an animal of the same species. This is heredity. 



Ancestry. — A newly conceived individual comes half from 

 its siro and half from its dam. These in turn owe their exist- 

 ence and their characteristics to their sire and dam. Then, 

 the farther back one goes in the generations of the ancestors 

 of a certain individual the less is the influence of each. 



The sire and the dam are each supposed to be directly 

 responsible for one-half of the characteristics of a given 

 offspring, the four grandparents one-fourth, the eight great 

 grandparents are responsible each for an eighth and so on 

 back. Each of the ancestors, however, in the entire pedigree 

 no matter how far back one goes is supposed to have some 

 influence on any particular offspring Sometimes this may 

 be so small that it is not noticeable. A pedigree is simply a 

 tabulation of the ancestors of an individual in their regular 

 order. It is usually written thus: 



f' . / Sire 

 Sire < -p. 



Offspring ] ^^^^ 



Dam ^ T-i 



Dam 



Sometimes a pedigree is written out by enumerating only 

 part of the sires or part of the dams. That is, going farther 

 with one or two lines of the ancestry and not the whole or all 

 the lines. This is manifestly unfair as an inferior line may be 

 left out when these have as much influence as the good 

 individuals in the pedigree. 



VARIATION 



It is frequently noticed that there is a marked resemblance 

 between the children of a family; also sometimes between the 

 children and one or the other of the parents. When certain 

 characteristics of one parent become visible to the exclusion 

 of those from the other parent, it does not mean that those not 

 showing are not there. It simply means that they are not 



