Morphological Aspects of Ageing in the Placenta 113 



time of parturition, but eventually die when they become 

 too large to be delivered. It would be interesting to investi- 

 gate both the cytology and the functional capacities of the 

 placentas of such postmature rabbit foetuses. In connection 

 with postmaturity, Masters (1952) cites three cases in women 

 of intra-abdominal pregnancy which were terminated by 

 Caesarean section at or near term, and the placenta allowed to 

 remain in the abdominal cavity; for three weeks thereafter, 

 active chorionic gonadotrophin and sodium pregnanediol 

 excretion was present. 



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