(Vor. 1 
312 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
hydrolysis had taken place; those kept at 16-20°С. showed a 
good growth but no visible cellulose hydrolysis; and in those 
maintained at 24-26?C. there was about the same extent of 
growth as in the preceding series but accompanied by a very 
evident cellulose hydrolysis, a distinctly clear zone of dissolved 
cellulose surrounding the region occupied by the fungous myce- 
lium. It is therefore evident that even with approximately the 
same amount of growth cellulose hydrolysis is much more rapid 
at the higher temperature. 
An effort was made to determine whether or not it is possible 
to “train up" more active cyto-hydrolytic strains of the Sclero- 
tinia and Penicillium in question. On the one hand, these fungi 
were grown for several successive generations on peach-juice 
agar—a medium in which the organisms show no cytolytic ac- 
tivity. On the other hand, these fungi were cultivated for sev- 
eral successive generations on paper-cellulose agar—a medium 
which is low in soluble carbohydrates, and one in which the 
fungi exhibit considerable cytolytic activity. Tubes of paper- 
cellulose agar were then inoculated with the fungi grown in 
these two ways and careful observations were made to detect 
any differences in cyto-hydrolytie activity. No differences 
developed, however, from which it would appear that the source 
of cultures of Sclerotinia or of Penicillium does not materially 
affect the cellulose-dissolving capacity of these organisms, 1. e., 
each fungus shows the same cellulose-hydrolyzing power wheth- 
er the organism was cytolytically active during the immedi- 
ately preceding generations or not. 
EFFECT OF THE FUNGUS ON PECTIC SUBSTANCES 
The power of organisms to change pectic substances has 
been considered an important factor in the disintegration and 
softening of host tissue by certain plant parasites. Before enter- 
ing into a discussion of the experimental phases of this subject, 
it will perhaps be well to give some idea of the present status of 
this question, as well as a very brief resumé of the extensive 
literature which has accumulated about it. 
Fremey (23, 24), in 1840, was the first to report an enzyme act- 
ing on pectic substances. This enzyme, which he isolated and 
called pectase, induced the coagulation of pectin, Fremey attrib- 
