Scientific Proceedings (113). 



protein dissolved, and have, therefore, compared the lytic action 

 of an inhibited culture with a freshly dissolved culture. In the 

 former case the amount of bacterial protein inoculated was very 

 small compared to the amount of bacterial protein in the turbid 

 culture. After 4 hours when the turbid culture had become trans- 

 parent and the inhibited culture was clear, whereas, the control 

 for the inhibition experiment already showed definite growth, both 

 tubes, the dissolved and inhibited culture, were filtered and the 

 lytic action of each determined in a series of dilutions. There 

 was practically no difference in the activity of the two tubes in 

 the interval that the tubes were observed. I intend to repeat 

 this experiment, using a greater range of dilutions and observing 

 at more frequent intervals. However, the amount of bacterial 

 protein dissolved does not seem to influence the activity of the 

 lytic principle very strikingly. 



This lytic principle is very active in a dilution of 1-10, dis- 

 solving a turbid culture in from 2 to 4 hours. In a dilution of 

 1-100 the culture is usually dissolved in 12 hours. But in most 

 cases the balance between the lytic action and the overgrowth 

 by the resistant bacilli is temporary. Sooner or later, in most 

 instances, the resistant bacilli win out, and make the transparent 

 culture cloudy again. I have made fishings of the resistant types 

 and tried the action of the lytic action on these bacilli. I have 

 found that it often takes longer for the lytic principle to dissolve 

 a resistant type than to dissolve the stock culture, but that, 

 eventually, it seems to clear up a culture of this sort also. The 

 resistant culture, on transplanting, seems to lose its resisting ability, 

 but I have not finished working on this point. 



I have tried to find a temperature where the lytic principle was 

 still active and the bacilli could no longer multiply, so that, if the 

 tubes had once become transparent, they would remain so. I 

 have found that the lytic principle acts more quickly at a tem- 

 perature of 4i°-42°, a turbid culture will become transparent in 

 half the time required for a similar tub at 37 0 C. These experi- 

 ments are still under way, and it is very much of a question whether 

 it will be possible to get the lytic principle to work where there 

 are no actively growing bacilli. Between 45 0 and 50 0 the lytic 

 principle is not active. 



