34 BREEDING 



black and white blood which will crop out at every 

 generation, although blue birds only are mated 

 every time. 



I gave an account of the above facts in an article 

 on Mendelian principles which I wrote for the 

 Country Home. An acquaintance, who kept fowls, 

 read the article, and said to me that though the 

 article as a whole was very interesting, what I had 

 said about Andalusian fowls was, of course, untrue. 

 " It stands to reason," she said, " that if you continue 

 to breed from the Andalusians alone you will ulti- 

 mately fix the strain. It is common sense." Let us 

 see what actually happens. When blue Andalusians 

 are mated together, birds of three types of colour are 

 produced in the following proportions : one black, 

 two blue Andalusians, and one white in every four 

 birds, on the average. The blacks are found to 

 breed true ; so are the whites. The Andalusians 

 when mated together again produce these three 

 types in the same proportions. The result may be 

 expressed in the form of a genealogical table, as 



follows : — 



Blue X Blue 



1. Black 2. Blue 1. White 



Blacks only 1. Black 2. Blue 1. White Whites only 



It is impossible to look at this table without 

 suspecting that the blue Andalusian is a hybrid, like 



