88 Proceedings of Boyal Society of Edinburgh. [sess. 
Summary. 
In the foregoing paper I have mentioned how the experiments 
were performed, and how certain difficulties which might lead to 
fallacies could be prevented. I traced the connection between 
enzymic activity of plant and animal life, showing that probably 
in the animal as well as in the plant an interstitial digestion 
was constantly at work. Although our knowledge of this 
question is still doubtful and obscure, one hopes that with the 
advancement of chemico-physiological science such a result may 
be confirmed, and may throw fresh light on the pathology of many 
obscure diseases. I then described the results of experiments on 
upwards of sixty extracts obtained by the glycerine process from 
the tissues of the rabbit, child, and the adult, both before and 
after death. Tables were next given of extracts of organs obtained 
in disease, and of tumours (sarcomata and carcinomata) and tuber- 
cular sputum. My results showed : — 
(1) The presence of pepsin, or a substance analogous to it, in 
all the tissues, normal and pathological. 
(2) The presence of a diastatic ferment in the larger proportion 
of the tissues examined — probably of the nature of 
ptyalin. 
(3) The absence of trypsin in the tissues, except in the pancreas. 
Reactions which may have depended upon trypsin 
occurred in the intestines and in certain of the OTgans 
obtained post-mortem. 
(4) That tissues which normally contained much glycogen 
formed an extract which reduced Fehling. 
(5) That pepsin is present to a marked extent in the lung and 
liver of the rabbit as well as in the stomach. 
(6) That the intestines contained a proteolytic ferment of the 
nature of pepsin. This result differs from that of most 
authorities. 
(7) That an inversive ferment was not obtained by the glycerine 
process of extraction from the intestines of the child or 
rabbit. 
(8) That an inversive ferment was rarely present in the tissues. 
