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Fred. J. Taussio- 



left at the point of entrance into the sinus is less pronounced. However, 

 such a fold can be distinctly followed through a considerable number of 

 sections. From the direction of the connective tissue fibres it can be 

 seen that both vulva and vagina enter into its composition. 



Fig. 2. Median sagittal section through lower portion of genital tract 

 (Embryo 2). F., fold; It., rectum; S., sphincter ani muscle; U., urethra; 

 U. S., lu-ogenital sinus ; V., vagina. Magnified 20 X. 



Embryo 3 {Fig. 3). Fetus 18 cms. in length, good state of preserva- 

 tion. The three layers of the vagina previously described are here also 

 to be seen in about the same stage of development. No vaginal lumen 

 can be distinguished. The convex bulb of the vaginal cylinder jjrojects 

 but slightly into the cavity of the sinus urogenitalis. There is no special 

 growtli of the posterior wall, and nowhere is there to be seen any fold^ 

 such as was found in Embr3'os 1 and 2. There is no proliferation of the 

 vaginal connective tissue. 



-Since the completion of this article, I was able to obtain a sixth embryo 

 and made serial sections of the genital tract. The embryo was 18 cms. in 

 length and in an excellent state of preservation. The conditions were similar 

 to those of Embryo 3. The vagina consisted mostly of embryonal connective 

 tissue, with a central, somewhat branching core of epithelium, a few cells in 

 thickness. At the point of its entrance into the sinus urogenitalis. there was 

 no sign of a connective tissue fold such as Nagel describes (Fig. 9). 



