146 College of Forestry 
ance of most of the mycelium within the wood upon the 
completion of the decay within any one portion, that the 
older mycelium has served its purpose, ceased to function 
and disappears, doubtlessly being dissolved by the enzyme 
excretions from the younger active hyphe. We know that 
the membranes of fungal hyphz consist of cellulose as a 
fundamental substance, its detection being rendered difficult 
by the presence of infiltrated substances, possibly of a pro- 
tein nature. As evidence of cellulose constituting the basis 
of fungal membranes, we find that young fungal hyphe in 
decaying wood frequently color violet with cellulose reagents 
instead of yellow or brown as do the older ones. When we 
consider that the chemical composition of the membranes of 
the fungal hyphe is not so unlike that of woody membranes, 
it seems quite likely that the non-functioning hyphee, under 
certain conditions, may be digested either by closely related 
or possibly the very same kind of enzymes which they for- 
merly secreted to effect the dissolution of the surrounding 
woody membranes. If such procedure occurred within de- 
caying wood, it is conceivable that, after a time, we might 
have a dissolution of the hyphz which, in this case, might 
be most complete within the individual pockets and be 
retarded at the boundary between two adjacent pockets just 
as was the case in the decay of the woody elements. In this 
way we might account for the final reticulum of matted 
fungal hyphee left surrounding the individual pockets where 
early in the course of the decay they were demarked by resis- 
tant zones of wood forming a reticulum at the same points 
which later come to be occupied by the reticulum of matted 
hyphee. 
Tur Merasoztic Propucts or Potyrporus PARGAMENUS. 
Enzyme Activity in Polyporus Pargamenus.— From the 
anatomical and microchemical studies of various woods 
undergoing decay through the agency of Polyporus parga- 
menus evidence was obtained that .several enzymes are 
secreted by the vegetative mycelium of this fungus. Thus 
the disappearance of starch, proteids, pectic bodies, cellulose, 
