THE FCETAL MEMBRANES OF MAN. 271 



of WHARTON, except at the attachment at the navel, where for a 

 short distance it may be peeled off as a special thin membrane. 



Condition of the Fvetal Membranes during and after Birth. 



As a conclusion to the account of the foetal membranes some further 

 remarks may be in place regarding their history at birth. 



At the end of pregnancy, with the beginning of labor pains, the 

 foetal membranes, which form a fluid-filled sac surrounding the em- 

 bryo, are ruptured as soon as the contractions of the musculature of 

 the uterus have reached a certain degree of intensity. The rupture 

 ordinarily arises at the place where the wall of the sac is pressed out 

 through the mouth of the uterus (rupture of the amnion). In con- 

 sequence the amniotic water now flows away. 



With the continuation and increase of the pains, the child is next 

 forced out of the uterus through the rupture in the foetal membranes 

 it is born, whereas the placenta and embryonic membranes usually 

 still remain behind for a short time in the cavity of the uterus. 

 Immediately after birth the union between child and foetal mem- 

 branes has to be artificially interrupted, by the tying and cutting oft' 

 of the umbilical cord at a little distance from the navel. 



Finally, the foetal membranes with the placenta are detached from 

 the inner surface of the uterus, and with renewed pains are discharged 

 to the outside as the after-birth. 



The separation takes place in the spongy layer of the decidua vera, 

 approximately in the region which is designated as the line of sepa- 

 ration in the diagram given by LEOPOLD (Plate II.). The after-birth 

 is composed of both foetal and maternal membranes, which are quite 

 firmly grown together: (1) the amnion, (2) the chorion, (3) the 

 decidua reflexa, (4) the decidua vera, (5) the placenta (placenta uterina 

 and placenta foetalis). Notwithstanding the growing together, a 

 partial separation of the individual membranes from each other is 

 still possible. 



After birth the inner surface of the uterus is one great surface- 

 wound, since by the detachment of the placenta and the deciduae 

 numerous blood-vessels are ruptured. Also during the first days of 

 childbed fragments of the spongy layer of the decidua vera and 

 serotina, which remained behind at birth, continue to be detached 

 from it. Only the deepest layer of the mucosa, that immediately in 

 contact with the musculature of the uterus, is retained. This still 

 contains remnants of the cylindrical epithelium of the uterine glands, 

 as has been already stated. In the course of several weeks it is 



