844 DR D. BERRY HART. 



structure of this part of the Vcagina, what may be termed its 

 columnar portion, and on the fact that in certain rare forms of 

 atresia classed with atresia hymenalis, a transverse septum is 

 found an inch from the actual hymen (v. also p. 365). 



In the two-months' foetus the urinogenital sinus is relatively 

 long, has the Wolfiian ducts at its upper part, and the bulbs 

 developing from them block it therefore, and probably block the 

 lower portion of the urethra too. The involution from below 

 perforates both obstructions, and this view explains, I believe, 

 the apparent urethial hymen seen so often. The urinogenital 

 sinus of the! early foetus is therefore represented in the adult 

 by the vestibule, lower portion of the urethra, and lower third 

 of vagina. 



In the adult iiumau vagina the Anlage is therefore as fol- 

 lows : — 



(1) The upper two-thirds of the vagina are derived from the 



ducts of Midler. 



(2) The lower third is due to the coalescence of the upper 



portion of the urinogenital sinus, and the lower ends of 

 the Wolfiian ducts. 



(3) The epithelial lining of the vagina is derived from the 



Wolfiian bulbs, which again are epithelial proliferations 

 of the lower ends of the Wolffian ducts. The vaginal 

 mucous membrane is thus epiblastic. 



The outline of the human vagina from a developmental point 

 of view is indicated in fig. 23. 



The Relation of the Origin of the Vagina to its Lymjjhatic 



8iLpj)ly. 



I take this part as it affords a very interesting comment on 

 the view I have advanced. 



As is well known, the lymphatics of the external genitals and 

 lower third of the vagina and urethra pour into the inguinal 

 glands — i.e., these receive the lymphatics of the genital tract 

 whose Anlage is the urinogenital sinus, while the lymphatics of 

 the upper two-thirds or Miillerian portion of the vagina join 

 with those of the cervix uteri to enter the hypogastric glands. 



How far the vascular and nervous supply of the pelvis is 



