664 m# HUMAN BODY. 



believe that not only is the act of sexual congress at best, from 

 a physical point _of view, a mere nuisance to the majority of 

 women belonging to the more luxurious classes of society after 

 they attain the age of twenty-two or twenty-three, but that a 

 very considerable proportion suffer acute pain from it such as, 

 if frequent, breaks down the general health. A Ipyin^ woman, 

 finding her highest happiness in suffering for those dear to her, 

 is very unlikely to let her husband know this, so long as she 

 can bear it ; but if the possibility is known it will not, per- 

 haps, need much acuteness in him to discover such suffering 

 when it exists, nor very much real affection to direct him- 

 self accordingly. In the class of cases referred to, rest of the 

 over-irritable and congested female organs is above all essen- 

 tial. The cause is frequently removable by simple, but skilled, 

 treatment; the desirability of rendering this available to a 

 woman in members of her own sex is now generally recog- 

 nized. 



The Intra-TJterine Nutrition of the Embryo. At first 



the embryo is nourished by absorption of materials from the 



soft vascular lining of the womb; as it increases in size this 



is not sufficient, and a new organ, the placenta, is formed for 



the purpose. A foetal outgrowth, the allantois, plants itself 



firmly against the decidua serotina, and villi developed on it 



burrow from js surface into the uterine mucous inSmbrane. 



In the deeper layer of this latter are large sinuses through 



which the maternal blood flows, and into which the allantoic 



T illi project. Blood is brought from the foetus to the allantois 



y arteries and carried back by veins after traversing the 



c pillaries of the villi, arid while flowing through these re- 



a ives, by dialysis, oxygen and food materials from the mater- 



kj blood, and gives up to it carbon dioxide, urea, and other 



c istes. There is thus no direct intermixture of the two 



n oods; the embryo is from the first an essentially separate 



\id independent organism. The allantois and decidua sero- 



,ina becoming inseparably united together form the placenta, 



which in the human species is, when fully developed, a round 



"hick mass about the size of a large saucer, connected to the 



mbryo by a narrow stalk, the umbilical cord, in which blood- 



essels run to and from the placenta. 



Ul Parturition. At the end of from 275 to 280 days from 

 ^'tilization of the ovum (conception') pregnancy terminates, 

 ei) d the child is expelled by powerful contractions of the 



