HOW CHARACTERS BEHAVE 145 
when the mixture is bred. This fact was long a great stum- 
blingblock to breeders, involving the business of improvement 
in unfortunate and, as we now know, unnecessary mystery. 
Mendel’s law of hybrids.! This so-called Mendel’s law, 
named for its first discoverer (I say first, for it was lost till 
rediscovered), attempts to predict what will be the real char- 
acter of the offspring of mixed or hybrid parents when the 
characters of the mixture will not blend. 
What really happens in such a case is this: The hybrid 
offspring, instead of possessing a new character which is a 
kind of mean or blend between the different characters of the 
two parents, will contain them doz, and when these hybrids 
are bred together, their offspring will be not of one but of 
three distinct kinds, namely, a group that is like the one origi- 
nal and pure parent, another group that is like the other 
original and pure parent, and a larger group that is hybrid 
like its immediate parents. 
For example, let x and y represent any two nonblending 
characters in separate individuals. What will happen when 
they are bred together, and when their hybrid offspring are 
afterwards bred among themselves ? 
The problem stands thus : One parent produces both + and y 
characters. The other parent also produces both x and y char- 
acters. What are the combinations that will take place? Mani- 
festly these combinations will follow the law of chance. In one 
case out of four the two +2’s will unite, making pure +’s (1°) ; 
in one case out of four also the two y’s will unite, making pure 
y’s (3); and in the two other cases the .r and the y will unite, 
making again xy offspring in numbers equal to both the others ; 
that is, the total result of breeding together a lot of hybrid indi- 
viduals with mixed characters + and y will be in the proportion 
1 Mendel, an Austrian monk, carried on experiments in his garden that 
brought out the principle here stated, but all of which was lost and lay un- 
known for many years. For a more extended account, see “Principles of 
Breeding,” p. 513. 
