CHAPTER III. 

 BREEDING. 



Definition of Breeding. — Poultry breeding is comprised of 

 those operations which deal directly with reproducing and 

 improving domestic poultry. It includes mating, incubation, 

 and selection. For convenience and because artificial incu- 

 bation has been so highly developed as to need treatment 

 in a separate chapter, only those phases which have to do 

 with mating and selection are discussed here. 



Physical Basis of Reproduction in the Female. — The organs 

 of reproduction in the female fowl. are the left ovary and the 

 left oviduct. The right ovary and oviduct are formed 

 at the same time as the organs on the left side, but 

 degenerate during embryonic life, and remain, if at all, 

 only as functionless rudiments. Lillie' suggests that this 

 fact would appear to be correlated with the large size of the 

 egg and the delicate nature of the shell, as there is not room 

 for two eggs side by side in the lower part of the body cavity. 



The functioning ovary appears as a cluster of many 

 spheres which vary in size from that of the normal egg-yolk 

 down to the point where they are barely visible to the unaided 

 eye. Each sphere is a more or less developed ovum or yolk 

 and is joined to the main stalk of the ovary by a stalk of its . 

 own called a follicle. 



A continuation of this follicle completely surrounds the 

 ovum as long as it remains connected with the ovary. It is 

 the rupture of the follicle along a preformed line or band, 

 called the stigma, and which marks the extremities of its 

 vascular system, that allows the ripe ovum or fully grown 

 yolk to escape into the oviduct. In counts of the total num- 

 ber of ova and ruptured follicles visible to the unaided eye 



' Development of the Chick. 



(89) 



