280 Drs. Lochhead and Cramer. Gilycogenic Changes [Jan. 1, 
Extracts of the placenta of the sheep and the cow were examined in the 
same way, and gave the following result :— 
Glycogen-splitting Ferment in Placente of Sheep and Cow. 
Maternal placenta. Fetal placenta. 
Species. Weight of Cu,0. Weight of Cu,0. 
(Difference.) (Difference.) 
gramme. gramme. 
Sheep 0 0084 0 ‘0052 
P 0 0068 0 0080 
Cow negligible negligible 
a 0 -0060 0 -0040 
The results reveal a marked difference between the placenta of the rabbit 
and that of Ruminants, the last-named animals yielding a much weaker 
ferment than the rabbit. It is a very interesting fact that this difference is 
reflected also in the glycogen content of the placentz of these animals. 
The maternal and foetal cotyledons of the placenta of the sheep were 
examined for glycogen in several cases. The material was obtained from the 
slaughter-house and extracted within half an hour after death. By extraction 
with hot acidulated water we failed to find any glycogen. Experiments with 
Pfliiger’s method of extraction with strong alkali, however, showed that the 
foetal cotyledons of the sheep’s placenta contain glycogen in traces to the 
amount of about 0°01 per cent. 
The glycogenic changes in the sheep’s placenta must therefore be very 
insignificant, and correspondingly we find a weak glycogen-splitting ferment 
in this case. In the rabbit, on the other hand, where large quantities of 
glycogen are dealt with by the placenta in a short time, we find a powerful 
ferment present in the placenta. The glycogen of the maternal placenta of 
the rabbit, which, as we have seen, is made use of by the embryo, must 
necessarily pass through the fcetal part of the placenta. This part contains 
such small traces of glycogen, if any at all, that they cannot be detected by 
microchemical methods. We must assume, then, that the plasmodium 
absorbs glycogen not as such, but in an altered form. At the same time we 
find that the foetal part of the placenta secretes a strong glycogen-splitting 
ferment, more powerful even than that of the maternal part. 
In view of these facts, it is difficult to avoid the conclusion that in the 
placenta the ferment is active during life. If we assume that it is found only 
after death, we would meet with the further difficulty, that a tissue—the 
foetal part of the rabbit's placenta—which contains no glycogen during life 
should suddenly develop a glycogen-splitting enzyme after death. 
