yr 
The Biology of Polyporus Pargamenus Fries (5 
strand formation persisted for a long time. Two blocks 
(1x 1x4 inches) of the sapwood of sugar maple (Acer sac- 
charum Marsh.), inoculated with germinated spores of 
Polyporus pargamenus, exhibited but very little evidence of 
decay even after six months. A similar block of yellow birch 
(Betula lutea Michx. f.) wood, inoculated by placi ing a piece 
of decayed wood in contact with it and keeping it ina euliure 
tube plugg ged with cotton wool, exhibited considerable decay 
in this period. 
Very successful cultures on wood were obtained by making 
inoculations on a larger scale, using fresh sapwood. A living 
yellow birch sapling about two inches in diameter was cut 
up into two-inch blocks, and these were split up into quar- 
ters, leaving the bark attached to the wood. <A dozen of 
these blocks were placed in a large Erlenmeyer flask and 
sterilized under high pressure. After the sterilization the 
blocks were inoculated with a piece of the inner bark of 
yellow birch containing actively growing mycelium, the 
latter having been cultured in a moist chamber for some 
time previous. The mycelium from this fragment of bark 
soon spread to the blocks of wood and rapidly attacked the 
inner bark of these. The mycelium that began to spread 
over the surface of the blocks exhibited the characteristic 
strand formation. In the course of a month or so, the myce- 
lium had completely covered the mass of blocks, filling up 
the spaces between them, and obscuring the strand formation. 
The culture was kept on a shelf in the labor: atory but was 
not exposed to the action of sunlight. It was retained for 
seventeen months, but appeared no different at the end 
this time than it did one month after the inoculation was 
made, and never during this period did it exhibit any signs 
of sporophore formation. At this time the writer left Svra- 
cuse, but sent for the flask two months later. When it was 
unpacked he was agreeably surprised to find that several 
abortive sporophores had formed at the margin of the flask 
where the mycelium had grown part way up the side. (Plate 
XIII.) These abortive sporophores consisted of small resu- 
pinate, hydnoid hymenia, all of which were characterized by 
