MAMMALIA. 



707 



Fig. 325. 



which the young animal obtains the milk provided for it is even yet a 

 puzzling question. Does the Ornithorynchus lay eggs, or produce 

 living young ones ? This is a query that has not been satisfacto- 

 rily answered ; and its generative apparatus is so nearly related to 

 that of an oviparous animal, that even anatomy throws but little 

 light upon the subject. 



Both in the male and female there is, in fact, but one vent, 

 that leads to a cloacal chamber resembling that of a bird, and the 

 entire organization of the sexual organs is 

 rather that of an egg-laying than of a vivi- 

 parous creature, as will be evident from 

 the following details respecting them. 



The penis of the male Ornithorynchus 

 is perforated by a urethral canal, through 

 which the semen passes, but not the urine; 

 its extremity, moreover, is terminated by 

 two tubercles, giving it almost a bifid ap- 

 pearance. This penis when in a relaxed 

 state is lodged in a little pouch in the floor 

 of the cloaca, from which it projects when 

 erected. 



The cloacal cavity, as in birds, gives pas- 

 sage to the feces and to the urine. The tes- 

 tes (a) and the vasa deferentia (b) resemble 

 those of an oviparous animal ; but, on the 

 other hand, there is a complete urinary 

 bladder (c), and moreover a pair of auxi- 

 liary (Cowpers) glands (d, d), organs 

 never met with except in the Mammiferous 

 class. 



(834.) The anatomy of the female or- 

 gans is not less singular. The ovaria 

 (Jig. 327, a, a) are large and racemose, 

 like those of a bird ; while the two oviducts 



or uteri (Jig. 326, a, a), as the reader may choose to call them, 

 open into the cloaca by two distinct orifices (c, c), situated on 

 each side of the urethra, derived from the bladder (b). 



It is to Professor Owen that science is indebted for all that is 

 known relative to the anatomy of the female Ornithorynchus 

 when in a gravid state, and his researches upon this subject 

 appear to establish the following interesting particulars. First, 



