NOTES ON CRYPTOPORUS VOLVATUS 
Sanford M. Zeller 
(With Plate 159 and i Text Figure) 
Cryioporiis volvatus is unique among polypores, for the pore- 
bearing layer is hidden by a volva. It is thus often termed the 
“ hidden-pore fungus ” or the “ volvate polypore.” During the 
fall of 1911, the writer frequently found this species on fallen 
coniferous trunks. Since that time, many specimens of it have 
been collected. They were growing from such hosts as Douglas 
fir (Pseudotsuga taxifolia), the western hemlock (Tsuga hetero- 
phylla), and white fir (Abies grandis). During the months of 
March and April, 1912, I had the opportunity of observing quite 
thoroughly the development of the sporophores of this fungus, 
and a few words might be said here to supplement what Peck 
(3) has already said concerning some advanced stages of the 
pileus. Two trees of Tsuga heterophylla found on the campus 
at the University of Washington were thoroughly infected. This 
gave splendid opportunity to observe the sporophores in different 
stages. 
The very young stages of the sporophores of Cryptoporus are 
globose and covered with a thick crust of reddish-brown resin 
exuded from the tree. As the button grows, this crust becomes 
thinner and thus the sporophore appears to grow lighter in color. 
Because of this coating of resin, no satisfactory method of killing 
and embedding for histological work was found. However, some 
free-hand sections were made and examined after staining with 
eosin. In the earlier stages the button is an undifferentiated mass 
of fungous filaments. The cortex is soft-fleshy, hygrophanous, 
and white. Soon a tiny spherical cavity appears in the center of 
the button, when the latter is from 3 to 4 mm. in diameter. This 
increases in size with the growth of the button and the fleshy tis- 
sue increases in thickness up to about 3 mm. Until the sporo- 
phore is about 12-20 mm. in diameter, the tissue is about the same 
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