1908.| wn the Placenta and Fetus of the Pregnant Rabbit. 273 
TOTAL FCETAL GLYCOGEN PERCENTAGE 
IB - 19 - 20 - Bl - BW-2B~- 2p - 2 - 2+ ’W - 2B - 2% 
DAYS. FCETAL WEIGHT ww Gru 
Fie. 2.—Both curves have the same abscisse indicating the days of gestation from the 
18th day onward. The ordinates of the upper curve represent the glycogen 
percentage of the foetal organism from 0:20 to 0°60 per cent. The ordinates of 
the lower curve represent the weight of the fcetus in grammes from 0 to 
30 grammes. The dotted lines indicate the two abnormal cases referred to in 
the text. 
There is, therefore, a distinct parallelism between the growth of the foetus 
and the percentage amount of glycogen which it contains. As we have to 
deal here with an organism in which the life and growth of each single cell is 
not autonomous, but is dependent upon the metabolism of the whole, such a 
relation does not necessarily imply, as has been commonly held, that the 
quickly growing cells themselves are especially rich in glycogen. Indeed, 
this is, as we have seen, not the case. But if, instead of considering a single 
cell, we look at the fcetal organism as a whole, a distinct interdependence 
between the growth of the foetus and the glycogen present in the organism 
becomes apparent. 
Attempts were made, by variations in diet and by injection of phloridzin, 
to alter the glycogen percentage of the placenta, in order to find out if a 
corresponding change could be produced thereby in the fcetus. a 
Lffect of Variation in Diet.—The results of the feeding experiments on the 
