THE REPRODUCTIVE ORGANS 75 



each possessing its own particular physiological 

 function. The first part lies immediately 

 ventral to the ovary and is known as the 

 infundibulum from its funnel - like form. Its 

 anterior end is expanded into long processes 

 which fringe an elongated, oblique slit-like 

 opening by which the ovum gains entrance 

 to the tube. Immediately succeeding the in- 

 fundibulum is the albumen - secreting part of 

 the oviduct. This forms more than half of 

 the total length of the tube, and is remarkable 

 for the thickness of its wall. The isthmus 

 connects the albumen region with a thinner 

 walled uterus ; and this is continued by a 

 comparatively narrow vagina, which opens into 

 the cloaca. 



Microscopically, the wall of the oviduct 

 consists of the following layers : — (1) A serous 

 investment furnished by the peritoneum. (2) 

 A muscular tunic divided into two strata. 

 The outer stratum consists of longitudinal 

 and spiral fibres, continuous, as shown by Miss 

 Curtis, with the muscular tissue in the dorsal 

 and ventral ligaments of the oviduct.^ The 



^ Miss Curtis was led to study the structure of the Hgaments 

 by the observation " that there is apparently a great disproportion 

 between the amount of musculature in the walls of the duct (except 

 in the uterus and vagina) and the degree of physiological activity 



