LYMAN: STUDIES OF HYMENOMYCETES. 
171 
are not set off from the parent hypha by sterigma or constriction, and 
show great variation in size and shape. Yet their spore nature seems 
to be conclusively proven by their separation from the parent hypha 
at maturity, and by their retention of the power of germination long 
after other parts of the sporodochium have lost all vitality. 
Germination of conidia. — A whole sporodochium transferred to the 
hanging drop, in twenty-four hours gives forth many germ tubes. 
When such a specimen is crushed to separate its elements, the origin 
of the germ tubes from the ends or sides of the conidia is clearly seen 
(pi. 20, fig. 52-55). Only in the case of immature sporodochia, in 
which the conidiophores still retain some protoplasm, do germ tubes 
arise from any but the terminal cells (conidia), except in the rare 
instances where two or three conidia are borne in chains (pi. 20, 
fig. 53). 
The germ tube from a conidium produces clamps immediately at 
all septa, while the mycelium from a basidiospore shows clamps only 
after four or five days of growth; but after the formation of clamps 
the mycelia in the two cases are quite indistinguishable. 
Formation of basidiosporic hymenium. — The hymenium first 
appears in the form of small, thin, white patches on the surface of the 
wood or bark. These patches enlarge, become confluent, and overrun 
and immerse the sporodochia encountered, finally forming an effused 
' layer. The process observed in the writer’s cultures does not differ 
from that which takes place in the field, so far as can be judged from 
the examination of specimens collected. The very young patches 
of hymenium are composed of erect hyphae grouped in cymosely 
branched clusters, the end cells forming basidia. The method of 
growth of these clusters appears to be similar to that described by 
Harper (’02, p. 8) and de Bary (’87, p. 301) for Hypochnus, where 
by a process of basipetal branching, cymose clusters are formed. As 
the patches enlarge and become confluent with their neighbors, the 
hymenial layer increases in thickness, and becomes compacted until 
it is impossible to separate the cohering elements from one another 
or to trace the process of branching, but it is undoubtedly a continua¬ 
tion of that described above. Cystidia appear only in well developed 
hymenia; they vary considerably in size and shape, sometimes being 
regularly attenuated upward, but frequently cylindrical or irregular. 
History of Aegerita. — The genus Aegerita has a large synonymy, 
and various writers in the past have regarded it as related to widely 
