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 



Ovciry 



Calyx orjyolh ScLcTi 



Last portion o/~duct I 

 opened showing f 

 completed egy J 



Pei^Soigre throviph 

 which, the 6ffS^ 

 ts expelled. 



After Dalton. 



Yb2J( ert,te7-irhy t?ie 

 /u?xn.el- •sKa.pecL 

 oviaLiLct 



Second poTtion, 

 o^ -the o\^idiJ.at 

 yArhere the ci.lbu.mirt, 

 is £or-m.eci 



J Third portion, whenff 

 \ the shell is euided 



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 



