397 
Physiology of the Genus Eidamia. 
at the base and pointed at the apex. They vary in size from 8 /z to 20 \x in 
length and 1*5 /z to 3*5 /z in basal width. The conidia are borne on the 
sterigmata in small groups, though occasionally small chains have been 
observed. They are slightly ovoid or ellipsoid, measuring 4 /z x 5 n or 2*5 /z 
x 4 fji, or they may be spherical, and in diameter 4-5 jjl. On potato mush 
agar conidia reached the size of 6 /z x 4 /z. 
The colour of a single conidium is difficult to determine. When present 
in masses on the white mycelium they are often intensely coloured and pass 
through a series of colour changes varying according to the composition of 
the culture medium, temperature, and the age of the growth. These masses, 
which are usually evident three days after inoculation, are at first white, 
changing to cream, mustard yellow, dull yellow green, cinnamon buff, 
Fig. 5. E. viridescens. Conidiophores on syn¬ 
thetic medium plus agar at 20° C. x 390. 
Fig. 6. E. viridescens. Conidiophores from a cul¬ 
ture on potato extract agar at 20° C. x 390. 
tawny olive, and elm green in eight days on potato mush agar (20° C.). At 
25 0 C. on the same medium and during the same length of time the sequence 
of colour changes is massicot yellow, mustard yellow, light bice green, light 
elm green, dark olive buff, and buffy brown. On synthetic nutrient agar 
after eight days the final colour was dark cress green, and a very character¬ 
istic grass-green colour occurred when the fungus was grown in an alkaline 
medium. Characteristic changes in colour occur from day to day on the 
different media employed. The colour is insoluble in alcohol, ether, or 
chloroform. Spores were shaken up well in ether, and the coloured suspen¬ 
sion of spores sank quickly to the base of the test-tube, leaving uncoloured 
ether above. The same experiment performed with chloroform showed the 
coloured conidia remaining suspended for a time and then gradually^rising to 
the surface, leaving the uncoloured liquid below. These experiments give 
an indication of the specific gravity of the conidia. 
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