On maize-meal agar and prune agar slight differences are observed. On maize-meal 
agar the pycnidial cushions are up to 8 mm. in diameter; on prune agar the form is 
somewhat different, the pycnidia! cushions are columnar, 5-6 mm. high and 3— mm. thick. 
They have a sterile base, which is usually rather smaller in diameter than the rounded 
head in which the pycnidial cavities are found. 
Sugar agar appears to be an ansuitable medium ; there is no aerial mycelium, and only 
a few small sterile sclerotia are formed. Potato agar is also an unfavourable mediam. 
On solution N. agar only a few small sub-spherical cushions are formed, which are 2-3 mm. 
in diameter, and show some internal differentiation, but none were observed in which 
mature pycnidial chambers were formed. 
The masses of conidia oozing out of the pycnidia are pale orange-yellow (Ridgway). 
Individual conidia are hyaline, thin-walled, with granular contents, and containing a few oil 
drops. The majority are ellipsoid in form, a few are sub-fasoid or sub-pyriform: they 
vary from 16-5-23-5 g in length and from 6-7-5 » in breadth, the greater number measuring 
18-20 u X 6°5-6-T u. 
Fig. 4 
Germinating conidia after 6 hours at 25° C. in hanging drop. 
A number of hanging drop cultures in Ward tubes, each containing a small number 
of conidia, were put into an incubator at 25° C. After six hours a considerable number had 
germinated (fig. 4). The form and character of the spore remained unchanged, and a single 
germ tube, 2-5-3 y thick, colourless and non-septate, had been produced at or near one pole. 
After twenty-four hours possibly 20 per cent. of the conidia remained unchanged and 
had not germinated. The remainder had lost their granular appearance and had “become 
slightly broader and more broadly rounded at the ends, the majority being 6-7-7-5 u 
broad. They were still quite hyaline, but had become septate: most commonly with 
2-transverse septa, but a few were 1-septate, and there was an occasional one which was 
3-septate. Those which were germinating had, with a few exceptions, produced two 
germ tubes, one from each terminal cell (fig. 5). 
The conidia, which had germinated in six hours, had developed considerably, and had 
produced elongated hyphae ‘which were septate and branched. 
