1899-1900.] Dr J. S. M‘Kendrick on Enzymes in Tissues. 85 
duodenum which contains pepsin. I think it probable that such 
an enzyme may exist along the whole intestinal mucous tract. 
Again, it was easy to obtain, by glycerine extraction, the enzyme 
corresponding to ptyalin or amylopsin. In all cases this enzyme 
was extremely active. It is possible that in the child there is more 
use for this enzyme than in adults, as ptyalin of the saliva and 
amylopsin of the pancreatic juice may not be present in sufficient 
abundance at such an early age, while in the case of the rabbit 
there is. a greater necessity for such a ferment, as the diet contains 
so much starch. 
II. Extracts of the Stomach. 
Glycerine extracts of the stomach of both rabbit and child not 
only gave reactions showing presence of pepsin and rennin, but 
also ptyalin or amylopsin. The conversion of starch into sugar in 
both these cases was very marked. I have not noticed in any text- 
book mention of ptyalin having been obtained by extraction of the 
mucous membrane of the stomach. This also may be a peculiarity 
of the stomach of the rabbit and that of the child, but it will be 
important in future to see what effect a glycerine extract of a well- 
washed mucous membrane of an adult stomach has upon starch. 
III. Extract of Rabbit’s Lung. 
A very interesting result was obtained from the extract of the 
rabbit’s lung. With 40 c.c. of 0’2 per cent. HC1, the extract 
caused 1 grm. of fibrin to become totally dissolved in a short time. 
The same result, although in a manner less marked, was obtained 
from the extract of the child’s lung. 
It seems strange that the lung of the rabbit should possess this 
power so markedly. Fibrin was digested by the extract of the 
lung as completely as by the extract of the stomach. Does the lung 
then contain pepsin in almost as active a form as it exists in the 
stomach 1 The significance of this result is not apparent. 
IY. Extracts of the Pancreas. 
Glycerine extracts of the pancreas of rabbit and child, and also 
of the pancreas from the eclamptic case, gave reactions which 
