1908.| wm the Placenta and Fetus of the Pregnant Rabbit. 277 
first. appears in the maternal placenta. In the first experiment the rabbit 
(Rabbit E) was killed when 21 days pregnant, and in the second (Rabbit F) 
when 27 days pregnant. The maternal liver, the placenta, and the fetal 
liver and fcetal bodies were analysed. 
The results, which are given in Table VII along with the control from 
the normal series, show very clearly that the placenta does not give up its 
store of glycogen readily to the maternal organism when the hepatic reserve 
runs low. The placenta guards its glycogen deposit so much more jealously 
than the liver that it appears as if the cells of the placenta had a greater 
affinity for glycogen than those of the liver. 
The weight of the placenta is not very much affected in the case of the 
animal killed on the 21st day of gestation. The differences which are found 
between the maternal and fcetal parts respectively of the phloridzin animal 
and the control animal compensate each other, and may perhaps be due to 
the crudity of the mechanical separation. If the weight of the foetal and 
maternal parts are added together, there is practically no difference, the 
figures being 3°2 for Rabbit E and 3:24 for the control animal. 
The placentze of the animal killed on the 27th day of gestation, which 
show a distinct diminution in their glycogen store, have been affected also in 
their growth. Although the weight of the maternal part is slightly higher, 
the weight of the fcetal part is so low that, even if the total weight. of the 
placenta is taken, a marked diminution is evident. The placenta of Rabbit F 
weighs 3°2 grammes, that of the control animal 4:13 grammes. 
The glycogen of the fcetal livers was estimated only in the second animal, 
as the first animal was killed at a stage when only traces of glycogen were 
likely to be present in the foetal liver. In the animal killed at the 27th day 
of gestation the weight and glycogen percentage were distinctly lower than 
in the control animal from the normal series. But the foetal liver still 
contained a much higher percentage of glycogen than the maternal liver 
(0-11 per cent.). 
The glycogen of the rest of the fcetal bodies was found to be reduced. At 
the same time the fcetal weight was decreased in both cases. 
The animal killed on the 21st day of pregnancy shows a diminution of the 
glycogen store of the foetus, while the placenta has yet retained its full share. 
A much more profound effect, however, has been produced in the animal 
killed on the 27th day. Here both the deposit in the placenta and that in 
the fcetus have been markedly diminished. Associated with these changes 
there is in both animals a retardation of growth, which again is more 
pronounced in the animal where the loss of glycogen has been greatest. It 
should be noted, too, that the retardation of growth is confined to the foetal 
