Chronological Changes in Placental Function 121 



PLACENTAL WEIGHT*(*VERAGEf j 



300 900 I SOO 



2250 3000 3750 -4000 5250 



4 FOETAL WEIGHTS IN GRAMS 



Fig. 4. Relation between placental and foetal weights in the 

 human. (After Adair and Thelander, 1925.) 



placenta, a function not possessed by the foetus. This synthesis 

 appears to be a steadily increasing function, as shown by 

 Table I. All the other mammals have no foetal fructose and 

 always appear to have much glycogen at some stage in the 



20 



UO 



160 



40 60 60 IOO I20 



SHEEP FOETAL AGE DAYS 



Fig. 5. Umbilical blood flow in the foetal sheep at different 

 ages. (After Cooper, Greenfield, and Huggett, 1949.) 



