28 



KANSAS UNIVERSITY SCIENCE BULLETIN. 



the tube b. Tube b is then plugged with 

 cotton, and the whole apparatus sterilized in 

 the autoclave. The stop-cock at c is left 

 open during the sterilization, so that the ex- 

 panding fluid may rise into tube b. After 

 sterilization the stop-cock is closed before 

 the liquid has sufficiently contracted to empty 

 tube b. When the apparatus has cooled, the 

 organisms to be tested are introduced into 

 tube 6, and the stop-cock opened enough to 

 let a portion of the inoculated fluid enter 

 chamber a. When gas is formed its pres- 

 sure is recorded by the mercury column in 

 ;tube d. 



This apparatus also makes it possible to 

 compare the growth of organisms in tube b, 

 which is freely exposed to the air, with that 

 in a, which is under nearly anaerobic con- 

 ditions. 



Three tests of the new race were compared 

 with similar tests of the check in this appa- 

 ratus, and the results are given in the table 

 below. 



In fermentation tube No. 1 gas is formed 

 under negative pressure, and under nearly 

 aerobic conditions. In the B. coll, as in the 

 yeast experiments, tubes of this form were 

 always used in pairs, with the new race in 

 one and the check in the other. The same 

 nutrient fluid was used for each, and in the 

 same quantity, 20 cc, and inoculations were 

 made from cultures previously grown under 

 smilar conditions. In the test of July 17, 

 1905 (see table below) , single filaments of the 

 new race and of the type were isolated just 

 before the test, and cultures made from the 

 offspring of these cells were used for inoculation. This was 

 done in order that the inoculated material of each type should 



Fig. 2. 



