386 BOTANICAL GAZETTE [DECEMBER 
in itself caused the greater growth by supplying nourishment, 
Zn not being a necessary or desirable element in a nutrient 
medium for fungi. Richards interpreted the function of the 
- zinc to be that of a stimulant rather than a food. May it not be 
that alcohol performs a similar stimulating function, rather than 
that it produces an acceleration of growth by nourishment? 
Whatever may be the correct explanation of the influence of 
alcohol on the development of the mold fungi, it seems to be 
demonstrated that the protoplasm of the molds is more sensitive 
in the conidial stage to the influence of this and most other dele- 
terious agents than at any other stage in their development. 
Potassium cyanid, KCN ; 2.2, 25.6, 77. Potassium cyanid in 
aqueous solution is very unstable. A solution of 24 per cent. 
KCN in pure water was prepared by the chemist, and on being 
used within three hours of titration gave the following critical 
points with Aspergillus and Penicillium : 
2 
e failed. 
Aspergillus in — grew, in 
Penicillium in 5 grew, in - failed. 
Ten days later this stock solution was again tested, having 
been kept in a dark cupboard at ordinary laboratory tempera- 
ture in the meantime, with the following result: 
n n 
i in — in. — failed. 
Aspergillus in a grew, in — aile 
nt . 
Penicillium in — grew, in — failed. 
64 32 
5 ‘ Ree 2) ee then made 
A solution in beet infusion containing 3 CN was 
k at a constant 
up from the stock solution and placed in the dar 
tested. 
temperature of 28° C. for 10 days longer and again 
The critical points were then as follows: 
a 
76 Brew: in ~ failed. 
Aspergillus in 3 
: nN . 
Penicillium in “ grew, in failed. 
I 
