The Proteases of Plants (V). 
BY 
S. H. VINES, F.R.S. 
Sherardian Professor of Botany in the University of Oxford. 
Experiments with Seeds ( continued ). 
I N a previous paper 1 I gave an account of some experiments on seeds, 
both germinated and ungerminated, which led to the following con- 
clusions : (1) that the ungerminated seeds contained (a) a protease that acted 
immediately on Witte-peptone, and (b) one or more proteases that acted 
more or less slowly upon the reserve proteids of the seeds ; further (2) 
that the germinated seeds all contained a protease that digested fibrin, and 
that such a protease was, in certain cases, developed in the substance of the 
ungerminated seed during the experiment. The difference in point of time 
between the action on Witte-peptone and that on fibrin, led me to infer 
that probably the two actions were due to two distinct proteases. The 
seeds used were those of Phaseolus multiflorits , Phaseolus vulgaris , Vicia 
Faba , Pisum sativum , Lupinus hirsutus , and Zea Mais. All of them, 
except those of Lupinus , are starchy seeds ; in Lupinus , which proved to be 
the most active proteolytically, the non-nitrogenous reserve-material consists 
mainly of the thickened cell-walls of the cotyledons (hemi-cellulose) and 
also of some fat in the cells. 
Since then I have confined my attention to oily seeds, more especially 
those of the Hemp ( Cannabis sativa ). I may say at once that I have found 
oily seeds to be much more proteolytically active than starchy seeds ; 
so much so, in fact, that I have experimented almost exclusively with 
ungerminated seeds. I should explain that I did not find it necessary to 
remove the oil from the seeds, as it did not appear to interfere with the 
progress of the experiments. I may add that various samples of Hemp- 
seed obtained from different sources were used, with but slightly varying 
results. The temperature of the incubator was 38° C. 
1 The Proteases of Plants (IV) ; Ann. Bot., vol. xx, 1906, p. 113, 
[Annals of Botany, Vol. XXII. No. LXXXV. January, 1908.] 
