178 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
of from one to several germ tubes (pi. 21, fig. 84-85), all of which 
bear clamps at once and develop into a mycelium indistinguishable 
from that arising from a basidiospore. 
Conidia. — Conidia appeared in all the w T riter’s cultures of this 
species, usually in great abundance. They belong to Preuss’s form- 
genus Oedocephalum, and strongly resemble the conidia discovered by 
Brefeld in his study of Polyporus annosus, save that they are of much 
smaller size and the eonidiophores regularly branch and proliferate 
repeatedly. These conidia are produced by both primary and sec¬ 
ondary mycelia, beginning within forty-eight hours after germination, 
and continuing throughout the life of the mycelium. They appeared 
on all media employed, although the production was diminished on 
very concentrated or very dilute decoctions. It w T as not possible in 
most drop cultures to follow the hyphal connection between the ger¬ 
minating basidiospore and the conidium, on account of the extensive 
interlacing of the hyphae; but by the use of very dilute liquid media 
this connection w r as incontestibly demonstrated. In such a culture 
vegetative growth is greatly abridged, and the entire development of 
the mycelia from basidiospore to chlamydospore and conidium is 
evident at a glance, without possibility of error arising through im¬ 
purity of the culture and consequent intermingling of foreign hyphae 
(pi. 21, fig. 78). 
The typical conidiophore (pi. 21, fig. 86) is a hyaline, erect, club- 
shaped hypha, from one and one half to tw 7 o times the size of the 
vegetative hypha (i. e., 3.5-4.5 y in diameter) and ending in a termi¬ 
nal enlargement or capitulum, 8.5-11 y in diameter. The upper half 
(or slightly more) of the rounded capitulum bears sterigmata whose 
number varies within wide limits, in normal cases being from 20 to 
40, although frequently eonidiophores with as few as 5, 4, or even 1 
are seen. The sterigmata are slender, cylindrical, or slightly attenu¬ 
ated upwards, and usually about tw r o thirds the length of the spores, 
although considerable variation is shown and the spores are sometimes 
almost sessile. The conidia (pi. 22, fig. 99) are hyaline, thin-walled, 
spherical or egg-shaped with a slight apiculus, 2.5-3 y X 3-3.5 y, 
and with finely granular contents. 
Development of eonidiophores and conidia. — Conidiophores appear 
on the older hyphae on the second or third day after the germination 
of the spore. They increase rapidly in numbers, and spread to all 
parts of the mycelium. 
