POULTRY DISEASES AND THEIR TREATMENT. 159 



"Some of the details of these remarkable processes deserve 

 attention : The observations of several naturalists demonstrate 

 that the ripe follicle is embraced by the funnel of the oviduct 

 before its rupture so that the ovum does not escape into the 

 body-cavity, but into the oviduct itself. Coste describes the 

 process in the following way: 'In hens killed 17 to 20 hours 

 after laying I have observed all the stages of this remarkable 

 process. In some the follicle, still intact and enclosing its egg, 

 had already been swallowed, and the mouth of the oviduct, con- 

 tracted around the stalk of the capsule, seemed to exert some 

 pressure on it, in other cases the ruptured capsule still partly 

 enclosed the egg which projected from the opening; in others 

 finally the empty capsule had just deposited the egg in the 

 entrance of the oviduct.' " 



"The existence of double-yolked eggs renders it probable that 

 the oviduct can pick up eggs that have escaped into the body- 

 cavity. But in some cases ova that escape into the body-cavity 

 undergo resorption there." 



"Immediately after the ovum is received l)y the oviduct it 

 appears to become softer and more flexible (Coste). The up- 

 permost portion of the oviduct then secretes a special layer of 

 albumen which adheres closely to the vitelline membrane and is 

 prolonged in two strands, one extending up and the other down 

 the oviduct; these strands become the chalazac; the layer to 

 which they are attached may, therefore, be called the chalazifer- 

 ous layer (Coste) of the albumen. The ovum then passes down 

 the oviduct, rotating on the chalazal axis, and thus describing a 

 spiral path ; the albumen which is secreted abundantly in advance 

 of the ovum is therefore wrapped around the chalaziferous lay- 

 er and chalazae in successive spiral layers and the chalazae are 

 revolved in spiral turns. The main factor in propulsion of the 

 ovum along the oviduct appears to be the peristaltic movements 

 of the latter; it is probable that the cilia which line the cavity 

 have something to do with the rotation of the ovum on its chala- 

 zal axis." 



With this account of the anatomy and physiology of the fe- 

 male organs of reproduction in hand we may proceed to a con- 

 siderations of their diseases. These diseases fall at once into 

 two classes: (a) those aflfccting the ovary and (b) those aflfect- 

 ing the oviduct. 



