346 THE URINO-GENITAL SYSTEM, THE ADRENALS, ETC. 



but do not communicate with each other ; the opening- of the right 

 tube is always slightly behind that of the left side (Fig-. 224 P). 

 From the papillae, into which the oviducts open, a fold of mucous 

 membrane extends backwards on the dorsal surface of the cloaca to 

 meet its fellow of the opposite side at an acute angle (Fig. 224 *). 

 The orifices of the ureters are placed within these folds. 



b. Minute structure. 



(i) The tubular portion of the oviduct has three walls: 

 a peritoneal covering with sub-peritoneal tissue (a); a glandular 

 layer (Jj) ; and an epithelial lining (c). Of these the glandular 

 layer forms by far the thickest layer^ especially during the 

 breeding season, when it is much increased in thickness. It 

 consists of long cylindrical glands, often bifurcated at their blind, 

 peritoneal ends. The epithelial cells, with which they are lined, 



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mf0^(3f(^^e 



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K 



III. 



© 



Preparations from ovary and oviduct. 



Ciliated epithelium and goblet-ceUs of the oviduct ; after Neumann. 

 Isolated goblet-cells and secretory cells from oviduct ; after Neumann. 



a, b, c Goblet-ceUs. 



d, e, f Secretoi-y cells after treatment with Miiller's fluid. 



X Stoma of secretory cells. 

 Surface view of the ovary ; after Kolessnikow. 



a Peritoneal endothelium. 



6 Gcrmiu il epithelium. 



have the power of absorbing more than a hundred times their own 

 weight of water (Boettcher). This layer is absent at the anterior 

 opening of the oviduct. 



