( 397 ) 



side of the mesonephros and is attaclied to it by a narrow band 

 (afterwards the mesorchiuin or uiesovarium) (Fig-, lin). The genital 

 ducts are developed on their whole length. The Wolffian duct 

 {iv.y.) joins transversal niesonephridial tubules in the mesonephros 

 but has no connection whatever as yet with the genital gland. The 

 Miillerian duct (Figure 1 '»■;/■) couunences with an ostium abdomi- 

 nale (o. a.) aiul runs as far as the region of the mesonephros is 

 concerned at the lateral side of the Wolftian duct. 



relation of the genital gland and genital ducts 

 in an indifferent stadium. 



k. genital gland. 



o.a. Ostium abdominale tubae. 



g.s. genital cord. 



w.g. Wolftian duct. 



m.y. Miillerian duct. 



s.it.g. Sinus uro-genitalis. 



FiR-. 1. 



We tirstly will follow the transformations, which appear in the 

 female sex. The first change is a reduction in the cranial part of 

 the mesonephros. Here nothing is to be observed that points to 

 a transformation of the mesouephridial tul)ules by renovation of the 

 epithelium. The Wolffian duct meanwhile grows cranially, remains 

 situated near the Miillerian duct, and moves then, passing archwise 

 through the mesovarium, to the ovarium, penetrates in it and there 

 ends blind (Figure 2 w. </.). The condition which issues from this 

 I have demonstrated in Figure 2 (Dasyurus 40 m.m.). 



Only now the reduction of the Wolffian duct begins. This occurs 

 in such a way, that the medial part disappears ; both at the cranial 

 and at the caudal extremity, a remnant of the duct remains. 



The cranial rudiment of the Wolffian duct is then found as a little 

 tubule blind at both ends, which commences in the ovarium and 

 can be traced till in the mesovarium. Figure 3 points out this little 

 tubule as I have found it in several animals (Dasyurus, Smin- 

 thopsis) (Fig. 3 w.y.). 



In how tar the remnant of I lie Wolffian duct lias i-elation to the 



2(j* 



