New York AGRICULTURAL EXPERIMENT STATION. 139 
or four days, while those in the heated tubes showed a similar 
but slower softening, requiring ten days for full action. 
In other experiments sterile blocks cut from turnip root and 
cotyledons of immature peas were used and were similarly 
softened. The results were fairly uniform and satisfactory. 
Various cultures so exposed at temperatures of 54°, 55°, 58°, 
60°, 62°, 63°, 64°, 65°, 68°, 73° were rendered sterile in prac- 
tically all cases. There was distinct cytolytic action in the 
sterile broths heated at the lower temperatures and none in 
those heated at the higher. There was, however, evident in- 
hibition of activity even at the lowest of these ag is shown 
in the experiment just described. Heating at 60°-62° inhibited 
the action to a marked degree as compared with 58° and in 
all cases, except one, heating at 62° entirely checked the ac- 
tivity. In only one case did any action occur in tubes heated 
at 63° and that was probably explainable on the ground of 
erroneous reading of temperature, since a repetition of the 
work gave results in harmony with the other series. No ac- 
tion occurred in any tube heated above 63°. The point of 
total inhibition of the cytolytic action as determined by this 
method, therefore, lay at or about 62° and there was marked 
decrease at all temperatures above 58°. Certain temperature 
relations will further be discussed later. 
STUDIES WHEREIN THE ENZYM WAS SECURED BY 
FILTRATION. 
It seemed probable that if the enzym were in solution out- 
side the bodies of the bacilli it would pass through the por- 
celain bacterial filters and so be obtained apart from the or- 
ganisms. Broth cultures of ages varying from seven to four- 
teen days growth have on six different occasions and with 
different bougies been passed through the Pasteur-Chamber- 
land filters and the sterility and enzym content of the filtrate 
tested. There has been no difficulty in securing sterility with 
Pasteur-Chamberland filters, although earlier attempts with 
thinner walled and probably less perfect bougies were not 
successful. 
