49 



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 

 afterwards. When the chicks are three months old the 

 first separation is made; males and females are sepa- 

 rated, 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 

 layers. 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 intelligently 

 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 2OO-egg hen. 



THE LAW OF SEX : MALES OR FEMALES AT WILL. 

 One of the most interesting problems that confronts the biol- 

 ogist is that of sex. What are the conditions that produce 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 poul- 

 try business offers a peculiarly favorable field for investigation. 

 When you reflect that perfect organisms may be produced in any 



