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HOW I APPLY THE PRINCIPLE OF SEX SELECTION.. 



And now I will tell the readers of this chapter how I apply 

 the principle of sex selection. I keep a close watch over my 

 chicks from the day they break the shell, and as soon as one 

 shows its sex that chick is marked so that I can tell it after- 

 ward. When the chicks are three months old the first sep- 

 aration is made ; males and females are separated, and the 

 chicks that showed their sex first are taken from the rest. 

 This gives me four flocks. From the chicks in which the sex 

 element first manifested itself I expect to get my best lay- 

 ers. When it is time to put the birds in the winter quarters 

 another separation is made the birds that show they are 

 nearest ready to lay are put in pens by themselves. (I do 

 not care for precocious pullets, but when pullets have had 

 time to mature the ones that are nearest ready to lay are in 

 my judgment the best pullets.) The final selection for the 

 breeding pens is made when birds are about 18 months old 

 the ones which moult the earliest and most rapidly being 

 selected for breeders. Thus by a consistent application of 

 the principle of sex selection I get my strain. 



With the males the same principle is applied. The birds 

 that show their sex the earliest and the most strongly are 

 reserved, and the others are killed and sent to the market. 

 Any judge will tell you that "good wattles are a sign of a 

 good bird." But besides having good wattles a breeding 

 cockerel should have other qualities ; he should be vigorous, 

 alert, courageous, well grown, with decided protuberances 

 on his shanks where later the spurs are to be. In other words 

 he should be strongly sexed. 



I believe that anyone who will consistently and intelli- 

 gently follow out the suggestions given in this chapter will 

 see his egg yield steadily improve, and that in three breeding 

 seasons, with comparatively little trouble, he will get the 

 200-egg hen. 

 THE LAW OF SEX: MALES OR FEMALES AT WILL. 



One of the most interesting problems that confronts the 

 biologist is that of sex. What are the conditions that pro- 

 duce a male organism and what the conditions that produce a 

 female? It is obvious that in a world where everything is by 

 law sex is not by chance, but what the law is we do not fully 

 know. Still many facts have been gathered, and we are 

 nearing the goal. The poultry business offers a peculiarly 

 favorable field for investigation. When you reflect that per- 



