On two species of Heterosponum particularly Heterosporium echinulatum gj 
was more irregular in outline than that of H from Beta . The colonies 
were most irregular in outline on plum-juice, salep and meat extract agar 
and least so on glucose agar (see hanging drop cultures). Upon glucose 
the growth was altogether more luxurious. 
1. Development of the Conidiophores. 
Spores sown on the afternoon of the 29 th Jan. produced mycelia 
with formed spores on 31 th Jan. i. e. after about 60 hours. The majority 
of spores were produced at night and in the early hours of the morning 
(temp. = 12°—15° C). Those formed in the early morning matured 
during the day, but no new spores were observed to be formed. During 
the following night and early morning more spores were formed and so 
on for 10—12 days. At 
such a stage the hanging 
drop cultures showed the 
original spore, the main 
hyphae from the germ 
pores, and branches from 
these hyphae which were 
not so thick. The original 
spores had been set upon 
the surface or in a dent 
in the surface of the nutrient 
medium (agar). The hyphae 
also grew upon the surface, 
and were covered with a 
thin film of water, which 
on account of refraction, 
made them difficult to ob¬ 
serve under high magnifi¬ 
cations. Some, however, 
grew just below the 
surface (cf. H. Betae\ Photomicro B. Young colony of Heterosporium 
which was easily made out, echinulatum in hanging-dropculture on salep-agar, 
for those within the agar showing coiled aerial hyphae (x 20). 
appeared as flat structures 
of two dimensions, the coefficient of refraction for agar and for the hyphae 
and their contents being about the same; whereas that of air is different, 
and hence the hyphae on the surface appeared as solid, i. e. as cylindrical 
structures with deeply shaded sides. Upon these main hyphae two sorts of 
branches were seen to exist, those which grew straight up into the air — 
the aerial hyphae — which were thin and coiled forming stiff spirals (Micro¬ 
photo B) and those which, a little thinner than the main hyphae from 
which they sprang, grew out in a horizontal direction. Some grew in 
and on the surface of the agar, and were, in fact, new nutrient hyphae, 
others, however, grew out towards the air. These latter were the young 
conidiophores, which grew out perfectly straight for some way and were 
quite colourless. They arose from the main hyphae in two ways, either 
one cell of the hyphae branching at one end (fig. 27 a) or a short cell itself 
growing out to form the branch (fig. 29 d). 
Mycologisches Centralblatt, Bd. II. 
6 
