MONOTREMATA. 



393 



seminal urethra. The physiological relation of The female organs of generation (fig- 191) 



these glands to such a canal is clearly illus- consist of two ovaria, the right much smaller 



trated by their presence in the Monotremes, than the left, two oviducts, two uteri, a clitoris, 



and their absence in the oviparous animals and mammary glands, 

 which have merely a seminal groove. 



Fig. 191. 



a, Cloacal outlet. 



b, Common vestibule. 



c, Uro-genital canal. 

 c', Its sphincter. 



d, Uterus. 

 d', Oviduct. 



e, Ovarian aperture. 



f, Left ovary. 



/', Right ovary. 



, Ovarian ligament. 



k, Urinary bladder. 



I, Ureter. 



in, Os uteri. 



Female oryam of generation, natural sixe, Ornithorhynchus. ( Owen, PIulos. Trans. 1832. ) 



