268 Drs. Lochhead and Cramer. Glycogenic Changes [Jan. 1, 
Table II.—Glycogen and Weight of Maternal Placenta (Distal Part). 
Average weight of maternal! 0°72 0°51 1 ‘30 1°60 1 34 1°73 
placenta in grammes 
Average weight of glycogen| 00320 0 02477 0 :0729 0:0858 | 0:0746 | 0-0931 
per placenta in grammes 
Glycogen percentage......... 4,-4.4, 4,81 5 66 5 36 5°57 5°40 
Day of gestation ...... 23. 24. | 25. 26. 27. 28. 29. 
Average weight of maternal} 1 °63 1°63 1°41 1°40 1 ‘28 1-08 0°56 
placenta in grammes | 
| Average weight of glycogen | 0°0731 | 0°:0733 | 0:0515 | 0:0392 | 0°0316 00-0162  0:0065 
per placenta in grammes | 
| Glycogen percentage ......... 4°50 | 4:49 |3-64 | 280 |256 (1:50 | 1°18 
merest traces. But in the last week of pregnancy the liver carries out this 
function for the foetus, while the placental glycogen gradually diminishes, and 
simultaneously with this the decidual tissue degenerates and is absorbed. It 
is this connection between the healthiness of the decidual cells and their 
store of glycogen, on the one hand, and their degeneration after the glycogen 
store has been absorbed by the syncytium, on the other, which leads us to 
suppose that they have a definite function to fulfil during pregnancy, and do 
not merely exist, as is usually stated, as pabulum to be absorbed by the 
syncytium. | 
A remarkable feature of the results is the absence of individual variations. 
The changes in the “ proximal glycogen” are tabulated in Table III, which 
gives the results of the analyses of the foetal placentze with the peninsule of 
the maternal placenta attached. Itis obvious that in this case no informa- 
tion 1s obtained by expressing the “proximal glycogen” belonging to the 
maternal placenta in terms of percentage of the fcetal tissue, which is mainly 
foetal in origin and the weight of which may, in fact, be taken as indicating 
the weight of the foetal placenta. It is worthy of note that the weight of the 
foetal placenta does not show a decrease in the last week of pregnancy like 
that seen in the maternal placenta. 
The variations in the proximal glycogen follow approximately those 
observed in the distal glycogen. On the 29th day there is no glycogen 
remaining in this part of the placenta. But up to a period within 48 hours 
