64 STUDIES IN COMPARATIVE ANATOMY. 



Mayer's account and the actual part whicli is now before us. 

 Shortly below the union of the Fallopian tubes, there is visible 

 externally a slight constriction. At the same point two con- 

 siderable and well-marked enlargements project inwards from 

 the internal wall and almost close the passage. Above this 

 point the uterine wall is more distinctly and closely plicate 

 than below. Hence the united Mlillerian ducts appear to us 

 to be plainly divisible (above the uro-genital canal) into 

 two parts, which are separated by a constriction and differ in 

 internal structure. The upper part seems to us to represent the 

 uterus, and the lower the vagina, while the internal thickening 

 may well represent an os uteri. It would be interesting to 

 know something of the gravid uterus of the elephant, and in 

 particular to ascertain by direct observation in what part of the 

 united sexual ducts the foetus is lodged, but we have no obser- 

 vations before us which bear upon this point. 



Vagina. 



The next division of the generative canal may be distinguished 

 as the vagina. It is about 9 inches long, and tapers upwards. 

 The walls are almost entirely destitute of muscular fibres. On 

 its inner surface a number of small and irregular rugse are seen, 

 some of which converge to an indistinct anterior and a posterior 

 raphe. 



Uro-Genital Canal. 



Close to the entrance of the urethra into the generative duct 

 a marked constriction is externally visible, and here, when the 

 peritoneum is removed, the outer surface, which was smooth 

 and membranous in the region of the vagina, becomes strongly 

 marked by circular muscular fibres. On opening the tube a 

 narrow passage serves as the only communication between the 

 proper vagina and the vulva, or uro-genital canal. This passage 

 is divided into lateral halves by a thick rounded cord covered 

 by mucous membrane, which is apparently a hymen.^ 



The uro-genital canal is more than twice as long as the pro- 

 per vagina, and when freed by dissection and extended, it 



1 It would be weU to ascertain, when an opportunity occnrs, whether this band 

 is ruptured by copulation or parturition, as the descriptions of Hunter and Mayer 

 indirectly lead us to suppose probable. 



