Vines.— Proteolytic Enzymes in Plants (II). 599 
The action of sections of stems and leaves was next investi- 
gated : and here again the number of positive results is much 
smaller than that of negative. Out of a list including about 
fifty species, only a few were markedly active ; namely, 
sections of the leaf of Dyckia princeps , of young shoots of 
Phytolacca dioica , of P. abyssinica , and of Portulaca oleracea . 
In the case of Phytolacca abyssinica , it is specially noted that 
sections of young tissues acted much more powerfully than 
those of older parts. 
In the case of roots, those which proved to be active were 
about equal in number (38) to those that failed to act, though 
in many cases the activity was slight. The most active roots 
were those of A morphophallus Rivieri , of Aspidistra elatior , 
and of an undetermined Bromeliad. The authors contrast 
the more general distribution of the enzyme in the roots 
with its more restricted distribution in the green parts, where 
its presence seems to be especially associated with rapid 
growth. At the same time they find reason for doubting 
if the penetration of the tissues of the parent member by 
endogenously developing roots is due in any degree to the 
action of the proteolytic enzyme ; in fact they assert that 
the ‘ poche digestive ’ of van Tieghem has no significance so 
far as the solution of proteids is concerned. In this connexion 
they mention that their researches were carried on in the 
month of July, when conditions were most favourable for 
ferment action. 
The number of bulbs, tubers, and tuberous roots examined 
was but small, only twelve, and the positive and negative 
results were equally divided. The tubers of Tamils communis 
and of Dioscorea bulbifcra, , as also the tubercular roots (con- 
taining Anabaena) of Cycas revoluta were found to be most 
active, whilst the root-tubercles of the Leguminosae acted but 
feebly. The bulbs examined were those of Allium sativum , 
Cepa , and Porrum , but they were not found to be active ; nor 
were the tuberous roots of Beta and of Dahlia , From these 
facts the conclusion, which seems to me to be hardly justified 
by the facts, is drawn that of these organs those that are 
