110 ROYAL SOCIETY OF CANADA 



lead color and blue-green. The culture became very slimy. In 8 days it 

 could be drawn out between two test tubes to a length of 2 metres and 

 when 1 c. c. of the culure was shaken with 10 c. c. of water, the liquid 

 was colored green-blue and could be drawn out in short threads. 



At 18° to 22° C. — In 24 hours there was growth but no inversion 

 of the sucrose; in 3 days growth had increased, there was strong inver- 

 sion and a green-blue pigment appeared. In 5 days the culture dre-r 

 out in tJireads. In 12 days the color was deep blue above and green- 

 blue below. 



At 25° to 27° C. — A number of cultures were observed. They' 

 usually became a little turbid in 24 hours and turbid with ropy white 

 sediment in 48 hours. In 66 hours cultures were so slimy as to draw 

 out in threads and there was a strong inversion of the sucrose. The 

 colors were as at the other temperatures, but the duration of the bright 

 color was shorter than at 18° to 22° C. In 20 days most of the pigment 

 was gone and the cultures were amber colored below. 



Pigmentation was hastened and intensified by inclining the tubes 

 so that the surface of the liquid was exposed to the air throughout the 

 length of the tube. 



Growth in Milk. — Separated milk, acid -f 17°, was filled into 

 sterile test tubes, 10 c. c. in each, and into small sterile Erlenmeyer 

 flasks, 100 c. c. in each. Merck's purified litmus was added to part of 

 the milk before tubing it. The milk was sterilized on 3 days in flowing 

 steam and was then incubated to insure sterility. Uninoculated con- 

 trols remained unaltered throughout the following experiments. 



Milk Flasks at 18° to 22° C. — Flasks of 100 c. c. were inoculated 

 with one 2 m.m. loopful of culture. In 24 hours there was usually no 

 change evident. In 25 to 40 hours a pale gray-blue or green-blue color 

 appeared diffusing downward -^the depth of the milk and the milk in 

 the surface layer became so slimy as to draw out in long threads. In 

 3 days the color zone was light blue and in 4 days bright blue. In 6 or 

 7 days peptonization began in a thin layer below the color zone and pro- 

 gressed slowly, being only 4 m.m. deep in 10 days. The peptonized 

 milk was amber colored, translucent and very slimy. From this 

 peptonized layer to the bottom, the milk was white and apparently 

 unaltered, as stained preparation from this part of the milk showed 

 few bacterial cells. Thus for 10 days growth was confined to a surface 

 layer. 



In 9 days cultures showed no coagulation even on boiling, Init in 

 20 days a soft curd had separated and settled. Except for some floating 

 pigment grains, all blue color was gone, the whey was amber colored 

 and about the consistency of the white of an egg. There was an acid 



