206 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE [VOL XII 
record in America appears to have been not earlier than 1886. There 
is some evidence that the Indians knew of its medicinal value. 
2. The active principle is a resinous substance, Agaricin; this, with 
other resins, constitutes up to 70% of the dry weight of the fruiting 
body. , 
3. The resins are secreted in the form of amorphous granules to a 
very slight extent on the mycelium, but in great abundance on the 
hyphae of the sporophore. 
4. Chlamydospores appear in cultures. They also occur on the 
sporophore, but in both cases are different from those produced by 
Polyporus sulphureus. 
5. The.context consists of a complicated system of strands more or 
less loosely bound together, and in consequence exhibits a characteristic 
areolated structure in sections. 
6. Quélet and certain other European systematists have assumed 
that Fomes officinalis is a variety of Polyporus sulphureus, or specifically 
very close to it. They are very distinct species, however, differing in 
many respects: (1) Size and branching of hyphae; (2) Form, longevity 
and content of sporophore; (3) Structure of sporophore; (4) Size of 
spores; (5) Distinct differences in cultural characters. 
7. Fomes officinalis is the cause of a red heart rot of conifers, charac- 
terized by a removal of the cellulose, by a fracturing of the wood into 
rectangular masses, and the formation of mycelial sheets in the crevices. 
Histologically, the effects are similar to those caused by Polyporus 
Schweinitzii. It occurs on living and dead timber, and belongs to the 
group commonly regarded as wound parasites. The losses occasioned 
by it in some areas are extensive. It occurs throughout Ontario and 
Quebec on Pinus Strobus, and has been reported from Michigan on the 
same host. 
8. Fomes officinalis is known to occur on the following hosts: 
Europe and Asia: Larix europaea, L. sibirica. vi 
America: Abies concolor, A. magnifica, A. grandis, Larix occt- 
dentalis, L. laricina, Picea Engelmanni, P. sitchensis, Pinus lambertiana, 
P. murrayana, P. ponderosa, P. Jeffreyi, P. strobus, P. monticola, Pseudot- 
suga taxifolia, Tsuga heterophylla, T. mertensiana. 
9g. In America, Fomes officinalis is reported from: 
Canada: British Columbia, Ontario, Quebec. 
United States: Arizona, California, Oregon, Washington, Mon- 
tana, Nevada, Idaho, Wisconsin, Michigan, Wyoming. 
