LYMAN: STUDIES OF HYMENOMYCETES. 
173 
CORTICIUM ROSEO-PALLENS Burt. 
PL 20, fig. 56-73. 
Collections of this species from well rotted oak logs at Stony Brook, 
Massachusetts, resemble Corticium rubro-pallens Schw., but were 
pronounced by Professor Burt to be a new species as yet undescribed, 
which he has previously known only in two collections of his own at 
Middlebury, Vermont, and in one by Professor Atkinson at Ithaca, 
New York. 
The hymenium is thin, rather broadly effused, pale rosy salmon- 
colored when fresh, but fading to almost white in dried specimens. 
The spores are small, 2-2.5 X 4-5 y, allantoid, with thin walls and 
clear refractive contents (pi. 20, fig. 57). 
Germination of basidiospores. — Although small and thin-walled, 
the basidiospores show great retention of vitality, a considerable 
percentage being still capable of germination after having been kept 
for six months in the laboratory in a dry condition. Germination 
in drop cultures is rapid, the spore swelling at once to several times 
its original volume, while the contents become more granular and 
develop one to several refractive guttulae (pi. 20, fig. 58). The first 
germ tube appears in from twenty to thirty hours, and is followed 
a little later by a second in the majority of cases; the spore finally 
becomes indistinguishable from the hypha or is marked only by a 
slight enlargement at the junction of the two germ tubes (pi. 20, fig. 
59-62). 
Nature of the mycelium. — The character of the mycelium arising 
from the germinating basidiospore varies. In some instances clamps 
appear at once on the germ tubes (pi. 20, fig. 60), but in the majority 
of cases no clamps are produced (pi. 20, figs. 59, 62). This primary 
clampless mycelium sometimes produces clamps after a period of 
growth, but more commonly the clampless condition persists during 
the entire life of the cell culture until the mycelium becomes exhausted 
by the production of conidia and growth ceases. The hyphae with 
clamps are somewhat larger, averaging 3-3.5 y in diameter, while 
those without clamps average 2.5-3 y. Growth is equally rapid and 
of the same character in both cases except that the formation of conidia 
is slightly more tardy on the clamped mycelia. On the latter, conidia 
first appear on unclamped branches of somewhat smaller diameter, 
