LYMAN: STUDIES OF HYMENOMYCETES. 
177 
growth of the former and is distinguished from it only by the presence 
of numerous clamps, not by increased size of the hyphae, as is the 
case in Corticium alutaceum (see p. 161). 
Conidia and chlamydospores are produced in abundance (pi. 21, 
fig. 78), but oidia were not observed in any culture. The life history 
is completed, after five or six weeks, by the production of extensive 
basidiosporic hymenia. In agar tubes, especially in strongly acid 
decoctions of prunes or other dried fruits, the hymenium first develops 
on the surface of the agar and afterward spreads far over the glass 
walls of the tube. Very extensive hymenia are also formed on wood 
cultures on Populus, Acer, Quercus, etc. The hymenia thus produced 
appear to be perfectly normal and agree in every w'ay with specimens 
collected in the field. Indeed, this species produces hymenia more 
readily and extensively than any other species which the writer has 
cultivated. 
Chlamydospores .— On the next day after germination chlamydo¬ 
spores begin to develop, and soon become numerous in all cultures, 
appearing on both primary and secondary mycelia in equal profusion. 
A young primary mycelium which has formed both chlamydospores 
and conidia is shown in figure 78 (pi. 21). In well nourished cultures 
there may be an extensive vegetative growth of the mycelium before 
the formation of chlamydospores, but in drop cultures made from an 
attenuated decoction of horse dung the mycelium is reduced to one or 
two hyphae, and chlamydospores occur close to the germinating 
basidiospore (pi. 21, fig. 79). In many cultures the production is so 
copious that old hyphae may possess rows of chlamydospores, adjacent 
ones being frequently separated by less than their own length of the 
empty hypha walls (pi. 21, fig. 80). 
The method of formation (pi. 21, fig. 81-83) agrees with the general 
description of basidiomycetous chlamydospores already given (see p. 
150). In general appearance, also, they are quite typical, save that 
they present an unusual degree of uniformity in size and shape. They 
are very regularly ellipsoidal or spherical with comparatively few 
imperfectly or abnormally developed individuals. In size they vary 
from 8.5 X 11.5 // to 16 X 17 y, averaging about 11 X 13 y. As was 
stated above, chlamydospores are produced on both primary and 
secondary mycelia indiscriminately, but on germination they inva¬ 
riably produce secondary mycelia. Germination is rapid in drop 
cultures, eighteen to twenty hours being sufficient for the production 
