STUDIES ON THE LIGNIN AND CELLULOSE OF woop. 57 
and careful examination of the material used should obvi- 
ate much of this difficulty however. 
ENZYMES OF FUNGI. 
Potter also states that, ‘‘ the delignification cannot be 
entirely attributed to an enzyme secreted by fungi.’’ As 
above stated it has been shown that the original thickness 
of wood fiber walls is very materially reduced by some 
agent at the very time when the fungus is attacking the 
tissues in question. It is also shown that the cellulose which 
may or may not be present in the walls defore they are at- 
tacked certainly is not the same unlignified cellulose which 
is present after the destruction of the wood by the fungus. 
It seems certain then that fungi do delignify woody cell 
walls. 
There can be no doubt that enzymes, or some substance 
exhibiting the characteristics of enzymes, have been proved 
to exist in some of the fungi and indeed in some of the 
wood rotting ones. Such investigations as have already 
been published in this connection would seem to prove be- 
yond any reasonable doubt that enzymes are secreted by 
fungi and that they are of the most varied character. 
Diastase seems to he proved to be present in many of the 
different fungi and in the wood rotting ones. The disap- 
pearance of starch in the early stages of attack of some of 
the wood rotting fungi upon wood seems to be generally 
attributed to the secretion of diastase by the fungi. Why 
should the disappearance of lignin from the fiber walls, 
leaving cellulose in the last stages of decay, be attributed 
to any other cause than the secretion of a delignifying 
enzyme until we have proof of some other agent which is 
capable of such action? ‘To be sure, the separation of an 
enzyme or a juice showing enzymic action from the fungus 
being studied is the exact proof of the existence of an 
enzyme; yet when we consider that enzymes are accepted 
