The book is: California Poultry Practice: Plain Hints for Beginners in the Rearing, Housing, Feeding, Protecting from Pests and Diseases and Marketing of Poultry Products you can download the book for free here: Google Book Search Page 29... "Mate your male bird with more females than ordinary and if they are older it won't matter. The eggs will not be so fertile as if you had less females with him but the bulk of the chicks will be pullets. And you can afford to lose a few eggs if you want pullets. Also the last eggs at the end of the season are nearly always pullets." I posted in this section of the forums, because this book ALSO has a VERY informative section on incubation. I learned a great deal already including the notion that the eggs SHOULD NOT be exposed to light during the incubation period. That's right.. no light. I also learned that we might just consider the phases of the moon when we're artificially incubating. Hope you enjoy the read, it's free.