108 



broth was used in making the inoculation, and there was plenty of water in the bot- 

 tom of the tube. After 7 days this tube was removed from the thermostat and kept 

 in the dark at room temperatures for 38 days, but no growtli ensued. 



(3) Three well-plugged tubes of 1:2 moderately litmus alkaline beef ])rotli (stock 

 245) were inoculated at the same time from the same tube, and in the same way. 

 Two of these were put into the thermostat at 40° C. and the other was kept at room 

 temperatures. 



Result: The check tube clouded on the fourth day and passed through a normal 

 course of development. The tubes in the thermostat remained ])erfectly clear until 

 the end of the experiment (45 days). 



(4) Three tubes of cauliflower broth (stock 217), which by long standing had dried 

 out one-fifth (2c.c. ), were also inoculated at the same time from the same culture 

 and in the same way. Two of these tubes were kept at room temperatures and the 

 third was put into the thermostat at 40° C. 



Result: One of the check tubes clouded on the third day, the other some time 

 between the fourth and seventh day. Both developed a yellow pellicle and threw^ 

 down a yellow precipitate. The tube in the thermostat was under oVjservation 45 

 days, but there was no growth. 



(5) Three tubes of 1:2 acid beef broth (stock 204) were each inoculated with a 

 large loop from a beef-broth culture of Ps. hyacinthi 7 days old. This culture, which 

 was moderately cloudy, showed many small zoogloeie floating in the fluid, and on 

 the bottom a small amount of decidedly yellow precipitate. Two of these tubes 

 were put into the thermostat at 36° to 38° C. and the third was kept at room tem- 

 peratures (mostly 21°). 



Result: On the third day the check tube became feebly clouded and contained 

 many tiny zoogluea?. On the eleventh day this tube was moderately cloudy, showed 

 a yellow precipitate, and bore on the wall of the tube at the surface of the fluid a 

 yellow rim of loosely adhering zoogkeae. An agar culture inoculated from the same 

 tube at the same time and kept at room temperatures also developed normally. 

 The tubes in the thermostat remained free from bacterial growth as long as the 

 experiment continued (22 days). 



(6) Three tubes of resistant glass, each containing 10 c. c. of strongly alkaline beef 

 broth (stock 286b, neutral to phenolphthalein), in which Ps. hi/adntJii was known to 

 grow well, were each inoculated with a loop from a clouded tube of alkaline beef 

 broth 6 days old. After remaining for an hour at room temperatures, 2 of these 

 tubes were put into the thermostat and kept at 35° to 36.35° C. during the first 5 days, 

 then at 32° to 33.50° for 24 hours, and afterwards at 34. 15° to 35.35°. The third tube 

 was kept in the dark at room temperatures ranging from 18° to 23° C, except on one 

 day when the room temperature fell to 8° C. Each of the tubes put into the thermo- 

 stat received a large loop of the cloudy broth; the tube left at room temperatures 

 received a smaller loop of this broth, i. e., not one-fourth as many germs. 



Result: In 43 hours the check tube was distinctly clouded. On the fourth day it 

 was well clouded, free from zoogkeje, and showed some yellow precipitate. The 

 other 2 tubes remained clear as long as they were left in the thermostat. One was 

 removed on the thirteenth day and left for 24 days at room temperatures (mostly 

 22° C. ), but no growth ensued. The other was removed on the sixth day and left at 

 room temperatures 31 days, but no growth ensued. At the close of the experiment 

 the tubes still contained 8 c. c. of broth, i. e., the concentration was not beyond what 

 this organism bears readily. 



(7) Three cylinders of sugar beet (stock 292) were inoculated at the same time 

 and from the same tube as the preceding, each tube receiving a large loop of the 

 cloudy fluid. Two of these tubes were i)ut into the thermostat along with the beef 

 broth (6), and the third was kept at room temj)eratures. 



Result: The check tube showed no growth at the end of the fourth dav, i. e., there 



