8 BOTANICAL GAZETTE | JANUARY — 
poor in content which have replaced the basidia. The latter, 
as in all true Basidiomycetes, collapse soon after their spores 
are ripened. . 
Whether this habit of forming new hymenia by proliferation — 
from those already exhausted is due to alternation of favorable 
and unfavorable conditions of moisture, etc., I am not sure. It 3 
is also uncertain whether a single hymenial layer may go on ~ 
indefinitely producing new basidia to replace those which have — 
the basipetal method of branching shown in De Bary’s figure. 
It would not result, however, in the formation of a second new 
hymenium, such as is shown in jig. To, and it seems quite © 
probable that the latter has been secondarily formed after a 
check to growth due to cold or drouth sufficient to stop the 
formation of basidia in the first hymenium. Whether a third 
hymenial layer might be developed in the same manner I have — 
not determined. No such case has been found in the material 
so far studied. 
It is interesting to note that, although the structures described 
for Hypochnus are extremely delicate and of microscopic size, 
the process of forming the new hymenial layers is essentially the 
same as that found in the larger stratified Polyporeae. Hypoch- 
nus, as we see, is really stratified, though not so described, and 
though lacking any markedly differentiated pileus. In the — 
large woody fungi of the stratified Fomes type the new hymenial 
