Abstract
In the protease systems of widely different plants there is always present a protease which can be activated by HCN and a dipeptidase which is inactivated by HCN. Depending on the proportion in which these 2 enzymes are present, the proteoclastic system of higher plants appears to be either activated or inhibited by HCN. The various specific proteases of the literature, as bromelin, papain, etc., are all to be considered as derived from a common enzyme type.