298 
W. B. Mercer, 
germination the spore frequently elongates, and divides in two by a cross 
wall (Fig. 3 , 4 , 6 , 8 )\ the elongated spore may become greatly pinched 
in where the cross wall is laid down, giving the impression of two distinct 
spores lying close together (Fig. 3 , 3 , 3 , 10 ). The bases of the germ 
tubes often swell irregularly (Fig. 3 , 5, y, 9 ). 
On Salep agar the spore swells very little and the germ tubes are 
narrower; in water the latter are only 2 9 broad (Fig. 3 , 13 — 21 ). On 
Lecithin gelatine they may commence as broad rounded buds, 7 —8 9 in 
diameter (Fig. 3 , 22 — 2 ?), though they develop later as normal tubes 
(Fig. 3 , 28 , 29 ). On Cane Sugar gelatine the germ tubes are usually 
irregular, and the spore does not greatly enlarge (Fig. 3 , 30 — 33 ). 
17 
6. The brown conidia. 
On the u Luft“-mycelium chains of conidia are formed in clusters or 
scattered singly (Fig. 3 , 34 — 40 ). The chains usually consist of a small 
number of spores, 
seldom more than 
five or six being at¬ 
tached together ; they 
may be branched or 
simple. The spores 
do not readily fall 
apart. When produ¬ 
ced in clusters, the 
chains are generally 
borne on a definite 
unbranched conidio- 
phore 5 —50 9 , in 
length (Fig. 3 , 34 , 
33 ), but isolated 
chains often arise at 
the end of long bran¬ 
ches which it is diffi¬ 
cult to regard as 
conidiophores in the 
ordinary sense of the 
word (Fig. 3 , 3 ? —jp). 
They occasionally 
spring from the wall 
of the pycnidium 
(Fig. 3 , 40 ). Hyphae 
bearing chains of co¬ 
nidia are not infre- 
Fig. 3. / — 27: Germinating pycnospores. — i — 12: on 
plum agar; 13—21 : in water; 22—27 : on Lecithin gelatine. — 
28, 2 q: Later stages on Lecithin gelatine. — 30 — 33: on Cane 
Sugar gelatine. — 34 — 39: Brown conidia on aerial my¬ 
celium on plum agar. — 40: The same on pycnidium wall. 
— 41—45 : Stages in development of brown conidia. — 
Fig. 1—33 = 353 / i; Fig. 34—45 = 153 /i- 
quently thick walled and dark coloured in the region from which the 
conidia arise. 
The spores are roughly pear-shaped, being drawn out at the apex 
into a beak which may be up to 30 9 long. They vary in length 
between 20 and 40 9 and in breadth from 15 to 25 9 . Not in¬ 
frequently they are oval, linear, or irregular in outline. They are smooth, 
thick-walled and divided by three or four cross walls; some of the cells 
