424 BOTANICAL GAZETTE [JUNE 
According to the first author, a watery extract of Botrytis 
mycelium caused, in thin slices of vegetable tissue, a dissolving 
of the middle lamellae and strong swelling and final dissolution 
of the cell walls. When such extract had been previously 
boiled no effect appeared. No statement is made as to any 
definite effect upon the cell contents. Kissling also assumes 
that a cellulose enzyme is the sole cause of the destructive 
effect. De Bary reaches the same conclusion in regard to Sed. 
Libertiana, but not without some apparent misgivings. At one 
point (p. 418) he says: “By a single brief boiling the juice 
[mycelium extract] loses its specific poisonous. effect,” but 
again (p. 421) “the difference [between the effects of boiled 
and unboiled extract] is to. be sure a quantitative one so far as 
can be observed. . . . . With the liquid from sclerotia the same 
differences appear, though less prominently; the boiled has here 
a relatively greater effect.’”” Behrens (10) found that boiling an 
extract of Botrytis mycelium did not destroy its injurious effect 
- ape plant tissue. 
__ It seems reasonable to suppose that a watery extract of the 
J ycelium of this fungus should contain any soluble substances 
secre iby the filaments, and have the same effect upon tissues, 
so far as" enzymes and any other soluble substances are con- 
cerned, as the fungus itself. In preparing such extracts the . 
s made use of the following method: Large flasks of oe 
id uid medium, usually prune juice, were eee ce 
ized, and then inoculated with Botrytis. A A vigorous. 
mycelium soon developed upon the surface, which was removed — 
and ed, then cut up into small fragments and finally ground 
pi a mortar with clean quartz sand. This pulp was then 
: a ee 2 d allowed to stand in a warm place for several 
earer portion was decanted off, -_ oe 
and strained. When vegetable ti ISSUE 
act the effect was very similar to th 
a . If a lettuce bane: was 
