76 College of Forestry 
the lack of a context and by the flattening of the teeth as in 
Irpex. In some cases where the mycelium had grown part 
way up the side of the flask the abortive sporophores had 
grown out from their points of attachment and farmed a 
few flattened teeth projecting downward as do the pores of 
normal sporophores. No normal sporophores possessing a 
context were ever produced in artificial culture. 
An effort was made to determine spore production. A 
sterile coverslip was lowered into the flask by means of a 
platinum loop fused imto a long glass rod, and placed under 
one of the abortive sporophores. On the following day the 
coverslip was withdrawn and mounted on a slide on which 
a drop of water had been placed. A microscopic examination 
revealed thousands of basidiospores, all of those examined 
having the characteristic shape and size of the spores of 
Polyporus pargamenus. These abortive sporophores con- 
tinued to shed basidiospores for several days, the spores 
tested being viable and germinating in the characteristic 
manner for the basidiospores of Polyporus pargamenus. 
It may be that the formation of sporophores previous to 
the time noted was retarded by the lack of an adequate 
supply of moisture within the flask since there was very 
little free water in the bottom of the flask when the experi- 
ment was started and none was introduced during the suc- 
ceeding eighteen months that the experiment was conducted. 
Upon examination the blocks of wood were found to be soft 
and spongy, and to have the same pocket type of decay char- 
acteristic of yellow birch wood when decayed by Polyporus 
pargamenus under normal conditions. 
The Vegetative Mycelium.— Two periods are clearly dis- 
cernible in the development of the mycelium of Polyporus 
pargamenus, and the mycelium pr oduced in these two periods 
will be designated respectively as primary and secondary 
mycelium. The primary mycelium is the product of the — 
germination of the basidiospore and is distinguished by the 
absence of clamp connections. The hyphe of the primary 
mycelium soon lose their protoplasm and disappear. The 
secondary mycelium arises from the primary in a few days 
