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JOHN A. ELLIOTT 
essentially the same. In all cases there was no resemblance between 
the normal and the abnormal mycelium (Plate XX: figs. i-6). The 
aerial parts of the colonies did not show reaction to the bacterial 
influence. 
Chro'mogensis on Rice 
On account of the chromogenesis exhibited by two of the species, 
cultures were made on boiled rice (i g. rice, lO g. water autoclaved at 
120° C. in test tubes). The colonies were allowed to grow for two 
months before comparisons were made, although it was noted that 
A. solani from potato, A. sonchi and M. sarcinula showed more or 
less marked chromogenesis within three or four days after inoculation. 
The most marked variations were those between the two strains 
of A. solani, which throughout the other experiments had shown many 
differences in reaction to media. A. solani from potato colored the 
rice light orange-red at the bottom of the test tube, deep orajige-red 
or brick-red at the lower limit of mycelial growth. The part of the 
rice through which the mycelium grew was dark-red-brown. The 
aerial mycelium was also red-brown. A. solani from Datura did not 
color the medium below the mycelium. The part of the medium occu- 
pied by the colony was dark gray or black. The aerial mycelium was 
white. A sonchi colored the medium lemon-yellow; A. iridicola, 
yellow-brown; A. fasciculata, A. tenuis, and A. dianthi light brown; 
A. brassicae var. nigrescens gave a very faint brown; A. hrassicae var. 
microspora gave no coloration. The medium was colored deep pink 
by Macros porium sarcinaeforme; blue-gray by M, sarcinula. 
The remarkable thing about the reactions of these fungi to various 
media was that it was impossible to predict from the reaction of one 
species, what the reaction of another would be. A case in point was 
the reaction to alkaline and acid media. A. hrassicae var. nigrescens 
showed a gradual increase in production of spores from high acid to 
alkaline media, the production in the latter case being very abundant. 
A. solani, from Datura, produced very few spores on the alkaline 
medium while on the acid media the spore production was abundant. 
Several species showed a lowered spore production in the acid media, 
notably those which normally produced few spores. Macrosporium 
sarcinaeforme, which usually produced spores in great abundance, 
produced none on the higher acid medium. 
Lack of nutritive substances affected all species alike, causing a 
