1881.] 



VAGINAL APPARATUS IN THE MACROPODID^. 



995 



body. The sections of the genital gland were compared with sections 

 of the ovary and testes of the young Rabbit (22-30 days)'; and the 

 structure was found to resemble the former rather than the latter, 

 although the state of preservation of our specimen is not good enough 

 to allow us to be certain. More satisfactory evidence is afforded by 

 the fact that two oblique folds meeting behind are situated on the 

 ventral abdominal wall, enclosing a rudimentary pouch. As we are 

 not aware that any such rudiment is found in the male, we conclude 

 that the specimen is a female. 



Our sections show the Miillerian ducts opening anteriorly into 

 the abdominal cavity. They pass backward along the margin of the 

 Wolffian body by the side of the Wolffian ducts ; as these two ducts 



Fig. 4. 



ws. 



a> 



nr 



a. Sketch of urogenital organs of young Macropus rvfus, from the left ventro- 

 lateral aspect, magnified. 



b. Diagram showing the arrangement of the duets : Bl, bladder; M. d, Miillerian 

 duct; ov, ovary; «.^, urogenital sinus ; 2«r, ureter; JF. 5, Wolffian body ; 

 W. d, Wolffian duct. 



pass backward they approach the middle line, the Miillerian duct 

 being the inner, the Wolffian duct the outer of the two, while the ure- 

 ters are external to the Wolffian ducts. Thus at first the Miillerian 

 ducts of the two sides converge ; they do not meet, however, the dis- 

 tance between them at their nearest point is three times the diameter 

 of the Miillerian duct. After converging, the ducts pass directly 

 outward, each accompanied by the Wolffian duct, to the outer region 

 of the mass of mesoblast, in which all three sets of ducts (Miillerian, 

 Wolffian, and ureters) are here embedded. They then turn backward 

 again, while the ureters pass inward to the bladder. From this 

 point the Miillerian and Wolffian ducts again converge. Posteriorly 



'^ These sections were kindly lent us by Mr. F. M. Balfour. 



64* 



