1908.] in the Placenta and Fetus of the Pregnant Rabhit. 281 
The objection that the glycogen-splitting power of the placenta is due to 
the presence of blood, which is known to have a diastatic action, is negatived 
by our results. The extracts of the placenta contained as much bloodiin 
Ruminants as in rabbits, yet the diastatic power of the placenta of the former 
was almost negligible compared with that of the latter. 
We wish to point out specially that the glycogen-splitting enzyme is an 
enzyme secreted by the cells. It is the only enzyme which we have been 
able to demonstrate in glycerine extracts of the placenta, although a large. 
number of experiments were made to test for the presence of tryptic, peptic, 
‘ ereptic, and lipolytic enzymes in these extracts. All these experiments gave: 
negative results. That such ferments are present within the cells of the: 
placenta as intracellular enzymes, and that their presence can be demonstrated, 
by using more severe methods than extraction with glycerine, we do not 
doubt. But such ferments, with the sphere of their activity limited to the 
cell itself, are present in the cells of many if not of all organs, so that their 
presence in the placenta would not throw much light on the function of this 
organ. 
On the Fate and Function in the Fetal Organism of Glycogen absorbed |. 
Jrom the Placenta. 
Whatever the source of the placental glycogen may be, its presence cannot 
be due to the accident of the anatomical site of the rabbit’s placenta, which, 
although identical in position with that of the cow and sheep, is distinguished: 
by its power of forming and storing glycogen. We cannot but recognise a 
definite function of the cells of the rabbit’s placenta of Hopeeiine) 2 a store. of 
carbohydrate for the foetus. 
There can be little doubt that the placental glycogen is absorbed by the 
plasmodium. It is situated, as we have seen, in decidual cells which are 
intimately related to the ectodermic tubules, and are, indeed, in Chipman’s 
words, “swallowed” by them, so that the glycogen contained in them must 
also be absorbed into the feetal structures. 
The quantitative relationship which we have proved to exist between the 
decrease in the placental glycogen and the increase in the fcetal glycogen 
affords strong direct evidence in support of the view that the placental 
glycogen forms a store for the foetus. 
A specific function appears to arise in the fcetal liver in the last week of 
gestation. If the hepatic store of glycogen were due to the favourable 
anatomical position of the foetal liver, we should expect to find the glycogen 
contents of the liver to be above that of the rest of the body during the 
whole period of gestation. We have seen, however, that up to the 24th day 
Z 2 
