UROGENITAL ORGANS 



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pocket also connects with the urogenital sinus so that a third vagina 

 occurs. 



In all placental mammals there is a fusion of the posteior ends of 

 the Miillerian ducts, which in the more primitive forms only includes 

 the vaginal region, the result being a single vagina, with two uteri 

 connected, each with its own opening (os uteri) into the vagina 



Fic. 399. — Uteri of (A) Ornithorhynchus; (B) Haimalurus; (C) sheep and (D) Inuus, 

 after Gegenbaur. b, bladder; bo, bursa ovarica; c, cornua uteri; cl, cloaca; /, ligament of 

 ovary; 0, ovary; od, oviduct (Fallopian tube); pv, processus vaginalis; sus, sug, urogenital 

 sinus; u, uterus; ur, ureter; v, vagina; vc, vaginal canals. 



(uterus duplex, fig. 400, //). This occurs in most rodents. Still 

 higher in the scale (carnivores, ruminants, horse and pig) the fusion is 

 carried farther, so that there is a single os uteri and the uteri are fused 

 only at the lower ends (uterus bipartitus, fig. 400, ///). Again the 

 fusion may be carried farther (uterus bicomis, fig. 399 C) in which 

 the double origin is still shown in the two horns at the proximal end. 



