66 MISSOURI BOTANICAL GARDEN. 
Tests for cellulose digestion were made with filter paper, 
ground to a pulp, and absorbent cotton, to both of which a 
stock solution was added. On the pulp a fair development of 
the mycelium resulted, with the production of spherical 
sclerotia, while on cotton only a slight growth was observed. 
These experiments were repeated several times, as so many 
authors have attributed the breaking down of the cell to a 
cellulose enzyme. Fehling’s solution showed only a slight 
reduction. The mycelial extract was allowed to act on pulp 
for a week, and when tested gave only a slight reduction. It 
may be assumed, therefore, that very little cytase is formed 
and that too much importance has been attributed to the 
role of this enzyme. 
A two per cent solution of castor oil produced a develop- 
ment not altogether normal. The oil lost its characteristic 
appearance and broke down into glycerin and fatty acids. 
Malic and tartaric acids gave a fair growth of mycelium, 
with few sclerotia and conidia. With oxalic acid no develop- 
ment whatever took place, even in low concentrations. 
With a two per cent solution of tannin, growth resulted in 
only one of six cultures and the effect of Botrytis on this sub- 
stance was not followed out, except that the culture was finally 
observed to turn black. Smith found that the tannin was 
broken down into glucose, gallic acid and a dark coloring 
matter which he was unable to identify. 
Amygdalin gave an excellent development of mycelium and 
conidia, but no sclerotia. Again no attempt was made to study 
the effects of the fungus on the medium. 
A solution of peptone produced an excellent growth and no 
changes in the medium could be detected. 
All of these experiments show that most of the carbo- 
hydrates, fats and protein derivatives used can serve as the 
sole carbon source for the fungus and that probably sub- 
stances in the plant cells belonging to the above classes may 
be digested by the enzymes secreted by the hyphal elements. 
The poisoning of the plant cells may be due to one or a num- 
oe iN et a ee 
