No. 4.] HEREDITY AND THE DAHIY COW. 17 



wagon to a star," and if we do that we may once in a while 

 get a good animal. 



Dr. R. W. Stimson. I was very much interested in this 

 elaboration of the breeding problem, and I would like to 

 ask Professor Trueman this question: I was attracted at the 

 outset by his figures for the white face and the red face. 

 He said, as I recall it, that if you breed the white face on 

 the red poll, you get all white face the first generation. 

 Then, if you breed a hybrid you get 25 per cent red face 

 and 75 per cent white face. Xow, supposing that you sub- 

 stitute " i\I " for " W," " M " meaning " milk," and " S," 

 or whatever else you get, meaning " scrub." Can you figure 

 in the second generation on 75 per cent fine milkers and 25 

 per cent scrub, or v/ill you keep on and get the proposition 

 of 25 per cent good stuff and 75 per cent pretty poor ? 



Professor Tkue^ma^^ The only way I can get out of that 

 (piestion — and I guess that is what I will have to do — is 

 just as the gentleman who spoke a moment ago said, that 

 we would have to take our chances. But before I answer 

 Professor Stimson's question that way, I don't want to leave 

 the impression that it is all chance, because I am satisfied 

 that the gentleman who spoke would make a good breeder 

 and would have good stock, and has had it, by doing just 

 what I said in the lecture, — selecting his breeding stock 

 from good stock and having just as many good ones in the 

 ancestry as he could get. Although we still must have the 

 chances, understand, I M^ould rather take the 75. per cent 

 chance than the 25 per cent chance, and that is what it rep- 

 resents. If I don't look after the ancestry of the animals I 

 am breeding, and take anything I can get, my chances are 

 small. jS^ow, if I am careful and do my selecting from good 

 animals, then my chance is better, and the better the chance 

 is the more careful I am in the selection of that offspring; 

 so that although there is a cliance, you understand, I would 

 say that in one case the careless handling of the stock repre- 

 sents a 10 or 15 or 25 per cent chance in your favor, while 

 the careful handling and selection represents a 50 or 00 or 

 75 per cent chance in your favor, which may mean all the 



