99 



was a well-clouded,' 43-hour culture in .<t<)ck 204. The germs were allowed to grow 

 in the hroth 1 hour, after which the tul>e was plunged for 10 minutes into water at 

 46° C. and then cooled at room temperatures. Result: Tul>e under observation 

 several weeks, but no growth. 



Check. — On December 3, at the same time as I, II, and III, another tube of stock 

 204 was inoculated with a large loop from tube 6, Decemlx^r 1 , and left at room tem- 

 peratures. Kesult: Growth was retarded, but not prevented. On the eighth day 

 the medium was still clear, but on the thirteenth day the fluid was faintly clouded 

 with a little precipitate and with good rolling clouds on shaking. This broth was 

 not titrated, and consecjuently its grade (^f a^-idity was not known. It was feebly 

 acid to litmus and containe<l a small amount of muscle sugar. 



IV. December S: Two tul>es of stock 204, one inoculated fromtul.)e 6, Deceml^er 1, 

 an<l the other from tube 7. December 1 (a beef-broth culture inoculated with 

 descendants of germs isolated from another hyacinth bulb). Each tul:)e receivetl a 

 large loop of the fluid, and as the cultures were some days older, more germs than 

 tubes I, II, III, and theiir check. After 1 hour both tubes were plunged for 10 min- 

 utes into water at 43.25° C, and then cooled at room temperatures. Result: Decem- 

 ber 11 lx)th tubes are faintly clouded; December 17, moderately cloudy with rolling 

 clouds on shaking and a small amount of yellow precipitate. The germs are not 

 killed by 43° C. and are little, if any, retarded, the two check tubes clouding in 

 about the same time and manner. 



Y. December S: Two tubes of stock 204, one inoculated from tube 6, December 1, 

 and the other from tube 7, December 1. In all respects a duplicate of IV, except 

 that the water bath was 44.3o° C. The tubes were coole<:l at room temperatures. 

 Result: December 11 both tubes are faintly clouded; December 17, no pellicle, but 

 a moderate amount of yellow precipitate and a good many small, roundish zoogloese 

 in the top layers of the fluid. These zooglceie diffuse through the fluid on gentle 

 shaking. Temperature of 44.35° C. does not kill or much retard growth. These 

 tubes were compared with the 2 check tubes mentioned under IV. 



VI. Deceml)er S: Two tubes of stock 204. one inoculated from tube 6. December 1, 

 and the other from tube 7, December 1. In all respects like V. except temperature 

 of water bath, which was 45.20° C. The tubes were cooled at room temperatures. 

 Result: December 11, both tubes perfectly clear. On December 17, when next 

 examined, the fluid in eai h tube was moderately cloudy, \y\'-h distinct rolling clouds 

 on shaking. Cloudiness easily v-isible without shaking. A little precipitate. Tem- 

 perature of 45.20° C. does not kill, but considerably retards growth, the 2 check 

 tubes (those mentioned under IV) being cloudy on December 11. The germs in tulles 

 6 and 7, December 1, were derived (as already state*, i from different hyacinth bulbs. 



VII. May 14: Six tubes of stock 217 (cauliflower broth feebly alkaline to neutral 

 litmus), each inoculated with a loop from tube ^. May 10 (stock 218, a potato broth 

 which came up slowly a.. L was moderately cloudy, with r» 'ling clouds on shaking). 

 Four of these tubes were plunged for Ivi minutes into water at 45.60° C, and two 

 were held as checks. Result: The tubes were under observ'ation for several weeks, 

 but all of them, including the two checks, remained sterile. There was no apparent 

 reason for the failure of the two checks, since the material used for inoculation was 

 living (see VIII), and closely related organisms grew well in this broth, e. g., Ps. 

 phaseoll. 



VIII. On May 14, from two tubes of litmus neutral beef broth peptone agar, two 

 pouretl plates were prepared in the following manner: 



(1) One cubic centimeter of the well-clouded potato-broth culture (tube 5, May 



^ It is possible that part of this clouding may have been due to dead or feeble indi- 

 viduals derived from the original inoculation, which was probably from a solid 

 culture. 



