eee ee eee 2S 
28 MISSOURI BOTANICAL GARDEN. 
light brown, and somewhat villous, in others it is entirely 
smooth, even shining as if polished, and dark brown. The 
older parts of the upper surface are dark brown, almost 
black, and are broken into many small pieces by numerous 
fissures. Many old sporophores have a jagged, extremely 
rough surface because of this fissuration. Lichens and 
mosses frequently cover the older parts. 
The lower side of the sporophore is dull red brown.*. 
The pores are exceedingly fine, so that they can scarcely be 
distinguished with the naked eye, measuring on the aver- 
age 108X143 uw; the dissepiments are about 108 mw in width. 
The interior of the sporophore is light brown, with evident 
though imperfect indication of stratification. The pores 
are continuous through several layers, remaining open for 
two or three years. They then become plugged at the base 
by the growth of hyphae from the walls of the hymenium. 
The plugging begins here and there in a particular layer 
and goes on irregularly. That the hyphae of the entire 
sporophore remain active is shown when parts of the 
sporophore are broken off, for then vigorous growth starts 
all over the broken surface, and in the course of a year 
one or more new sporophores have started, which gradually 
cover the broken surface and give the wholemass a peculiar 
appearance. 
The hymenium consists of short club-shaped basidia 
which bear four spherical brown spores, which appear to 
ripen very rapidly. They are discharged into the pores, 
and can be noted escaping from the openings in clouds, 
particularly on moist days. During June and July active 
discharge was going on. Cystidia are absent from the 
hymenium; the paraphyses, in the earlier stages, project 
out into the pores for a short distance, and not infrequently 
masses of spores are collected about their tips. A very 
striking fact is the large number of spores which never 
* The color approximating an equal mixture of yellow orange shade 
No. 1, and yellow orange dark, Milton Bradley color scale. 
