1916] 
ZELLER—PHYSIOLOGY OF LENZITES SAEPIARIA 495 
PROTEASE 
Proteolytie enzymes have been commonly demonstrated in 
the filamentous fungi, especially Aspergillus and Penicillium, 
but in the higher forms they are not so well known. The first 
to discover protein-digesting enzymes in the Basidiomycetes 
were Bourquelot and Hérissey ('95) who found that pieces of 
the white of an egg, which had been eooked for 10 minutes 
on a water bath, were changed when placed in the juice ex- 
pressed from sporophores of Polyporus sulphureus. The solu- 
tion gave a slight biuret reaction after incubating at 29-30°С. 
for 21 hours. Hjort (’96) found in the sap from the sporo- 
phores of Pleurotus ostreatus a tryptic ferment capable of 
digesting fibrin. It worked best in acid solutions and pro- 
duced leucin, tyrosin, and tryptophan. The naturally acid 
watery extract of the sporophores of P. sulphureus readily 
digested fibrin, but if neutralized or made alkaline it did not 
act at all. The expressed juice, weakly acidified with hydro- 
chloric acid or oxalic acid, digested fibrin as well as the 
original extract alone. After 12 hours of digestion the action 
was carried to peptones only. There were no amino acids 
present. 
In 1898 Bourquelot and Hérissey investigated the same 
action of the expressed juice of Ше sporophores of Amanita 
muscaria, and found it to digest nearly all of the caseinogen 
of skimmed milk in 4 days, after which tyrosin was present 
in the solution. Kohnstamm (701) investigated the proteases 
of Armillaria mellea, Merulius lacrymans, and Polyporus 
squamosus. The expressed juice from the sporophores of 
Armillaria mellea liquefied neutral thymol-gelatin to the ex- 
tent of 1 mm. in depth in 10 days. The gelatin tubes were 
8 mm. in diameter. Both the mycelium and sporophores of 
Merulius lacrymans were used. The juice from both was 
equally active in liquefying gelatin, about 8 mm. in 10 days 
or equivalent to 0.6 ee. The active principle is thermolabile. 
In a 0.2 per cent solution of hydrochloric acid the extract 
digested fibrin to peptone but not to amino acids, while in 0.2 
per cent sodium carbonate solution there was no digestion of 
fibrin. The juice of sporophores of P. squamosus, collected 
