URINOGENITAL ORGANS 



367 



stance of the testis (hermaphrodite gland or ovotestis), and one testis may 

 even be replaced by a rudimentary ovary. In these cases, the Miillerian 

 duct may be as well developed as in the female. 



The ovaries of Urodela are always formed on a common plan : 

 each consists of an elongated closed tube, with a continuous lumen. 

 In Anura, on the contrary, the ovarian sac (Fig. 293) is divided up 



'-- ot 



FIG. 293. URINOGENITAL ORGANS OF A FEMALE Rana escidenta. 



Ov, left ovary (that of the right side is removed) ; Od, oviduct ; Ot, abdominal 

 aperture of oviduct ; Ut, the dilated posterior end of the oviduct ; P, 

 opening of latter into the cloaca ; ^V, kidneys ; S, S l , apertures of urinary 

 ducts into the cloaca, surrounded by longitudinal folds (*), which are 

 separated by a deep depression (t). 



into a longitudinal row of numerous (3 to 20) separate pockets or 

 chambers. The oviducts open far forwards into the body-cavity by 

 funnel-shaped apertures; they take a tolerably straight course 

 along the outer borders of the kidneys to the cloaca in young 

 animals, but become greatly convoluted later. A short distance 

 from its termination each oviduct in Anurans becomes dilated to 

 form a thin- walled sac, and, after becoming again narrowed, usually 



