9 
The Biology of Polyporus Pargamenus Fries 83 
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other material with which to test the vitality of dessicated 
mycelium, the failure of this test does not deter him from 
thinking that the mycelium of Polyporus pargamenus should 
retain its vitality as long as that of its near relative, Poly- 
porus versicolor. 
The extreme xerophytism of Polyporus pargamenus is 
shown by the ability of its sporophores to revive occ: lao 
the second year. In the fall of 1915 the writer located : 
dead black oak bearing numerous sporophores of Paes 
pargamenus at its base. When observed, the sporophores 
appeared to be somewhat old and weathered, although cer- 
tain of them shed copious quantities of spores upon being 
revived, while others shed few or none. From this fact it 
would appear that this crop of sporophores probably devel- 
oped in the early spring of 1915. Frequent observations 
were made on this particular tree to determine whether a 
new crop of sporophores would be produced and whether any 
of the old ones would revive and continue growth. No 
growth whatsoever was to be seen until the middle of June, 
1916, when it was noted that a whitish mould-like growth 
Was appearing at the base of certain of the sporophores. On 
some the growth appeared on the upper surface; on others 
the new growth made its appearance as a new hymenium 
beginning to form over the old one; and in still others a new 
growth appeared simultaneously on both sides. Opportunity 
to examine the progress of this growth was not afforded until 
early in the fall of 1916. At this time the growth evidently 
was complete. The upper surfaces of certain sporophores 
were found to be covered with a new mold-like growth of 
hyphe, causing them to appear grayish. The presence of 
this new layer of hyphz gave the sporophores the appear- 
ance of being of the current year’s growth. On many sporo- 
phores a new hymenial layer developed over the old one, 
either partially or entirely covering it. Where new growth 
was put out on both sides of the pilei the resulting sporo- 
phores appeared to be just as normal in structure as the 
original ones, excepting that they were extraordinarily thick. 
A few sporophores, in addition to putting out a new growth 
