RESORPTION OF CONCEPTUSES. 287 



last group of cases the exact status can not be discerned from 

 the histories alone. However, since there is no endometrium or 

 at most a partial one, to shed, genuine menstruation manifestly 

 can not occur throughout pregnancy. It seems more probable 

 that the cases of supposed uninterrupted menstruation fall into 

 the last group although it is not impossible that rarely hemor- 

 rhage may occur only at the dates of normal recurrence. This 

 would seem possible because of the defective inhibition of the 

 returning normal impulses exercised by the dead or dying con- 

 ceptus and the retrogressing corpus luteum. This conclusion 

 harmonizes with the tendency to abortion which seems to be 

 present at the time of periodic hyperemia and hyper-irritability 

 in some of these cases. 



Although dissolution of the embryo or fetus alone has long 

 been known to occur, there seems to be no convincing evidence 

 in the literature for the occurrence of intrauterine autolysis and 

 absorption of entire conceptuses. Moreover, as already stated, 

 it is to be doubted very seriously whether complete intrauterine 

 absorption is possible after the formation of the skeleton has 

 been well begun. The fetal parts at this time are so resistant 

 that the uterus is stimulated to expel the macerated remnants 

 long before absorption of them can occur. Furthermore, com- 

 plete absorption would also seem to be hindered by the physical 

 conditions which obtain in the human female. Only as long as 

 the decidua capsularis is relatively thick, and hence effectively 

 prevents the escape of the products of autolysized embryonic 

 tissue, would complete absorption of a young uterine conceptus 

 seem to be possible. The same thing probably is true in some 

 cases of tubal pregnancy although the occurrence of early and 

 repeated, yes, even prolonged, hemorrhage in them makes com- 

 plete intra-tubal absorption much less likely. However, that 

 complete intrauterine absorption actually does occur in the human 

 female, it is the object of this article to establish. 



The occurrence of missed abortion and also of missed labor 

 long have been matters of common knowledge among physicians. 

 But these are phenomena usually connected with the later 

 months of pregnancy. In the overwhelming majority of these 

 cases the fetus was retained for a considerable period after its 



