68 FEMALE UROGENITAL ORGANS OF PERAMELES, 



of birth in Perameles as seeming " to be without parallel in the- 

 whole mammalian class." As regards the first point, I shall 

 show in the present account that in reality the pseudo-vaginal 

 passage leads away from the posterior ends of the united median 

 vaginal cul-de-sacs which themselves arise as outgrowths of the 

 Miillerian ducts at the junction of their uterine and vaginal 

 sections; while as regards the second, I hope to bring forward 

 sufficient evidence to show that the mode of birth in Perameles 

 must be almost exactly paralleled by the parturition phenomena 

 seen in those Marsupials which like Perameles give birth to the 

 young through a direct median passage. 



If for the expression " common uterine canal " the i-eader sub- 

 stitute " common median vagina," the main facts in my previous 

 short account of the parturition phenomena remain substantially 

 correct. 



The following account is based on the examination in serial 

 sections of the female urogenital organs of nine specimens of 

 Perameles, some of which were shortly described in my previous 

 paper. 



The specimens include the following : — 



i. P. nasiita, with two new-born young. (Stage E of pz'e- 

 vious jDaper). 



ii. P. obesula, with two 17 "5 mm. young in pouch. 



iii. P. obesula, with two 22 mm. young in pouch. (Stage F of 



previous paper), 

 iv. P. obesula, with four 3-7 cm. young. 

 V. P. obesula, with several 4 cm. young. 

 \i. P. nasuta (?), bred. 



vii. P. nasuta, with early blastocyst in uterus. (Stage A of 

 previous paper), 

 viii. P. obesula, with blastodermic vescicle in uterus. (Stage B 

 of previous paper), 

 ix. P. obesula, with two 12-5 mm. young in uteri. 



