308 OX THE ANATOMY OF 



two bra (" einfacJie Gebannutter mit doppeltem (redden und linJcen) Mutter- 

 mund" I. c. p. 104). Nevertheless I see no reason for doubting the view- 

 adopted by Prof. Owen, that the genital tube above the urethral opening 

 represents in reality both uterus and vagina. 



The presence of a vaginal septum, a remnant of the coalescence of the 

 primitively paired Miillerian ducts, in MyrmecopTiaga is a peculiarity 

 shared, judging from Owen's account, by the genus Cholcepus * only 

 amongst other families of Edentates. 



In the Indian Elephant there is, at least sometimes, a similar but 

 more perfect septum dividing into lateral halves not only the vagina, but 

 the uterus (here provided with a distinct os uteri) also t. In other cases 

 this disappears completely, except externally, forming then the so-called 

 " hymen" of Miall and Greenwood. 



In the genus Lagostomus, on the other hand, as first described by Prof. 



Owen J, the accuracy of whose statement I have lately had an oppor- 



P. Z. S. 1882, tunity of verifying, this median septum is developed along the proximal 



p. 299. (uterine) part of the vagina, instead of the distal (external) as in Myr- 



mecopJiaga . 



As Pouchet, though describing the two apertures, does not mention 

 any median septum, it is possible that this vaginal septum may disappear, 

 as there seems to be good reason for supposing that it does in Elephas 

 indicus, in the gravid state. The penis in Myrmecophaga is so small that 

 during coitus it is, I expect, entirely contained in the urine-genital tube, 

 and does not enter the vagina, as is also the case in Eleplias ; the disap- 

 pearance of the vaginal" septum can therefore hardly be due, in this 

 species at least, to the non-virgin condition of any particular female. 



4. As regards other points, I may mention that the external and 

 internal iliac arteries come off separately, as in many other mammals ||, 

 there being no common iliac arteries. 



* " In the Unau (Bradypns didactylus) the rudiment of a uterine septum appears as 

 a longitudinal ridge from the inner surface of the anterior wall in the unimpregnated 

 state : in this species also [the same condition having been already noted in Bradypus 

 tridactvlus\, the utero-vaginal canal communicates in the virgin animal by two dis- 

 tinct orifices with the short urogenital tract." Anat. Vert. ii. p. 690. 



t M. Watson, " On the Anatomy of the Female Organs of the Proboscidea," Trans. 

 Z. S. xi. p. 116 &c. pi. xxii. fig. 1. 



J P. Z. S. 1839, p. 177 ; Anat. Vert. iii. p. 686. 



A similar condition of things to that here described in the genus Myrmecophaga 

 occurs sometimes, it may be observed, as a malformation, known as " vagina duplex ct 

 uterus simplex" in the human female, the vagina being more or less completely divided 

 into two chambers by a median septum, and opening externally by two quite separate 

 orifices. C'f. a paper by Dr. T. Matthews Duncan, Journ. Anat. Phys. i. pp. 209-274, 

 and Dr. Morrison Watson's paper, " The Homology of the Sexual Organs illustrated 

 by Comparative Anatomy and Pathology," I. c. xiv. pp. 60-62. 



II Cf. P. Z. S. 1881, p. 188. 



