234 Transactions British Mycological Society. 
type appear frequently, and another common form is that de- 
picted in Pl. IX, fig. 2c. In almost any culture also, conidia 
may arise from the mycelium without the formation of a 
conidiophore. 
As the mycelium increases in size, strands of hyphae of a 
considerable thickness are often formed, and parts of these 
become at times almost black. They are often covered with a 
mass of conidia. From these coremia, as from the ordinary 
mycelium, conidia may arise without the production of a 
conidiophore. About the fourth day a new type of fructification 
arises—the Graphium form, which, as Miinch notes, is probably 
the Graphium penicillioides Corda. The Graphia appear in great 
numbers along the streaks and are easily visible to the naked 
eye as stout cylindrical pillars surmounted by a spherical head 
(Pl. IX, fig. 4). Each one arises from a group of short swollen 
cells of the mycelium, numerous branches of which grow up 
together to form a thick strand, the lower part of which becomes 
quite black, while the upper part remains colourless. The hyphae 
forming this stalk are very narrow and not infrequently the 
outer cells are slightly twisted round the stalk (Pl. IX, fig. 4 a). 
The apex is at first pointed but later spreads out, the colourless 
hyphae branching and from these branches the very small (3-4 
long, I-5—I°75 w wide) colourless conidia are cut off. When the 
Graphium is mature the head consists of a drop, milky below 
where the spores are collected but quite clear above. This drop, 
unlike that on the beak of the perithecium, mixes quite readily 
with water. 
In older cultures, small Graphia often grow out from the 
main head, while the Cladosporium conidiophores may sprout 
from the stalk, producing a most complicated looking structure. 
At the end of two weeks, perithecia begin to appear, a peri- 
thecium often arising at the base of a Graphium. The time of 
appearance of the perithecia however, is rather variable, for 
sometimes without any apparent difference of conditions, they 
have been delayed until the sixth week, and, as Miinch also 
found, their number is very variable, some cultures being 
studded thickly with perithecia, while others on the same media 
and under the same conditions, produce only a few. I have even 
had some without perithecia at all but with an enormous growth 
of mycelium. If, however, a piece of this mycelium was trans- 
ferred to another agar plate perithecia were invariably produced. 
The perithecium commences as a tangled mass of hyphae 
which are first a light, then a very dark brown, and finally 
decidedly black. For some time it grows as a dark spherical 
body invested with very fine, light-brown, hair-like hyphae. 
From its upper surface the beak then arises as a cylindrical 
