266 Drs. Lochhead and Cramer. Glycogenic Changes [Jan. 1, 
added—1 c.c. of the alkali for each gramme of tissue—and kept in a 
boiling water bath for some hours. The same was done with the foetal 
placente. The average weights of these two tissues per foetus may be seen 
in Tables II and III. Then the fcetal lvers were excised, care being taken 
not to include any of the intestine, and to empty the gall-bladder, which was 
always distended with a viscid greenish-yellow fluid. The livers and the 
remainder of the foetal bodies were weighed, and each set placed in a stoppered 
flask of known capacity and treated like the maternal placentz. ach tissue 
was liquefied by the strong alkah, except the foetal bones. The rest of the 
process was carried out in every respect as Pfluger recommends. 
The results are set down in tabular form in Tables II to V. As the 
number of placentz and fcetuses varied, it was necessary for purposes of 
comparison to calculate the results per placenta and fcetus in each case. It 
may be pointed out that the amount of glycogen given in these tables does 
not represent the total amount of glycogen actually obtained in each analysis. 
This can be found by multiplying the amount given for each case with the 
number of foetuses for that day given in Table I. 
A. Glycogen of Placenta. 
For a better understanding of the results, it is necessary to give a brief 
account of the anatomical plan of the rabbit’s placenta with its glycogen 
areas according to Chipman. In the maternal placenta, three parts can be 
recognised :— 
(1) That next the uterine muscle which represents the plane of separation 
of the placenta at the end of gestation ; 
(2) An intermediate part, the region of the uterine sinuses; and 
(3) A part which extends up as a series of peninsule between the fcetal 
columns. These columns are analogous to the villi of the human 
placenta, and are described by Chipman as ectodermic tubules with a 
plasmodial covering. 
Glycogen Areas.—In the maternal placenta, the glycogen is always con- 
tained in decidual cells, and three glycogen areas can be distinguished. 
(A) At the zone of separation. A definite quantity of glycogen is still 
present in this part at the end of gestation. 
(B) In the region of the uterine sinuses lying in the multinucleate 
decidual cells surrounding them. Here there is probably no glycogen left at 
the end of pregnancy. 
(C) In the peninsular projections. This is the part most intimately 
associated with the fcetal tubules, and, indeed, these projections are entirely 
covered by foetal ectoderm. 
