THE OVIDUCT 



301 



network of fine blood vessels. The upper opening of the oviduct 

 is expanded in the shape of a funnel to facilitate the entrance 

 of the ovum when it emerges from the yolk sac. The duct on its 



Ovary 



Calyx 



La^st portion of duct 

 opened 

 completed eg 



PeLS^cLO'e 'through 

 which, the 

 i& expelled 



Yolk e 



funnel- -shaped, 

 oviduct 



Second 



ovid-u,c,t 



the albumin, 



i<s formed 



(Third portion, vrhere 

 \ the shell is added 



Vent or olo&ca. 



FIG. 145. Female reproductive organs. 



way to the cloaca lies in folds, being lapped upon itself three times 

 before it finally passes into the cloaca. 



When the yolk enters the oviduct it consists of a yellow mass, 

 called the " vitellus," enclosed in a thin membrane, the " vitelline " 

 membrane. Fertilization takes place in the upper part of the ovi- 

 duct before any albumin has been added, and if at this time the 



