vi PKEGNANCY PAETURITION PUEEPERIUM 227 



included, as is also that of the clots of blood adhering to the after- 

 birth. Sfameni estimates the weight of the maternal placenta 

 at 408 grms. and that of the two other parts of which the 

 secuudines are composed the umbilical cord and the membranes 

 at 33. and 49 grms. respectively. The proportion between the 

 weight of the placenta and that of the foetus is therefore not 

 1 : 6-7, but 1 : 778. 



Pio. 92. Human placenta, uterine surface. (Chiarugi.) c, a cotyledon ; /, umbilical cord ; 

 m, membrane of ovum continuous with the circumference of the placenta. 



It is much debated among obstetricians whether causal 

 relations in the development of mass exist between the foetus and 

 the placenta, that is, whether the foetus regulates the development 

 of the placenta according to its own requirements, or whether, on 

 the contrary, a greater development of the placenta determines an 

 increased development of the foetus. The statistics of Pozzi and 

 Brizio would seem to bear out the latter view. Sfarneni on the 

 other hand has succeeded in proving the fallacy of the calculations 



