1914] 
COOLEY—SCLEROTINIA CINEREA 315 
and the filtrate treated with 95 per cent alcohol until a floccu- 
lent coagulum of pectin was produced. This pectin was sepa- 
rated by means of a Buchner filter, redissolved in water, reprecip- 
itated with alcohol, again separated by means of a Buchner 
funnel, and finally dried at a temperature slightly higher than 
room temperature,—the reprecipitation being for the purpose 
of purification. It should be noted here that the plums were 
sufficiently acid to make the addition of hydrochloric acid to 
the aleohol unnecessary. | 
Experiments with pectin and pectinase.—From the pectin 
isolated by the above method a saturated aqueous solution was 
prepared—some of the mineral nutrient solution! minus calcium 
being added, and the resulting solution rendered sterile by frac- 
tional sterilization. Test-tubes of this pectin solution were 
inoculated with Sclerotinia cinerea and Penicillium expansum 
with the result that both organisms produced a rather vigorous 
growth of mycelium and a few spores. At the expiration of 
one week the inoculated tubes showed a slight clear area just 
below the fungous felt due to the coagulation and settling out 
of the pectin in that part of the solution. The coagulation was 
at this time somewhat more pronounced in the Penicillium cul- 
tures than in those of Sclerotinia, yet very noticeable in both 
cases, beginning directly below the fungous felt and progressing 
toward the bottom of the tube. After two weeks the greater 
part of the pectin solution was coagulated, the flocculent coagu- 
lum, or precipitate, being very different from the precipitate 
produced in a pectin solution by a calcium salt. It should be 
emphasized here that every precaution was taken to maintain 
a calcium-free solution, and when it is considered that the addi- 
tion of calcium develops a reaction very different from that 
produced by the enzyme, and, furthermore, that the check gave 
no coagulation whatever, not even when allowed to stand a 
month or more, the conclusion would seem to be warranted that 
calcium is not necessary for the production of a gel by pectinase. 
Both Sclerotinia and Penicillium, therefore, produced a coag- 
ulum in an aqueous solution of pectin, while no such results 
were obtained in the controls, thus justifying the conclusion 
iNutrient solution employed was the same as mineral nutrient solution A used in 
preparing cellulose agar, but without the calcium. 
