22 



KANSAS UNIVERSITY SCIENCE BULLETIN. 



cept the glucose experiment fermentation continued longer 

 in the new race. 



The amount of gas resorbed by each type approximately 

 seventy-two hours after the maximum was reached is as fol- 

 lows : 



Table II. 



Date of 

 experiment. 



May 10 . 

 June 16 . 

 June 27 . 

 July 8. . 



Mediam. 



Glucose broth 



Saccharose broth. 

 Maltose broth. . . . 

 Saccharose broth. 



New race, 

 cc. 



12.0 



10.6 



5.1 



21.7 



Parent 

 type, cc. 



4.9 

 13.6 



8.0 

 22.4 



The chief aim of these experiments was to compare two 

 organisms ; and, while every precaution was taken to keep 

 the two under the same conditions during any one experiment, 

 no especial pains were taken to have the temperature and re- 

 action of medium exactly similar in the different tests. This 

 may explain tlie discrepancy between the two saccharose tests 

 of June 16 and July 8. 



Summarizing, the new race seems to have a greater power 

 of fermentation, but this was not the case in all experiments, 

 nor to any marked extent. 



In the experiments bearing on the relative resistance to 

 drying and high temperatures of the two types, the same new 

 race was used as in the fermentation experiments. To de- 

 termine resistance to drying, cells were subjected to long 

 drying at 35° C. to 40° C, to shorter drying at higher 

 temperatures, or to both. Their resistance to higher moist 

 temperatures was ascertained by exposing them in gelatin 

 or liquefied agar to temperatures ranging from 50° C. to 70° 

 C. for periods of from five to ten minutes. Throughout all 

 these experiments the parent type as a check and new race 

 were exposed to exactly similar conditions. Roll cultures 

 were used for the most part, and a large number of cells sown 

 in each tube. 



Of eight dry-heat experiments, two showed small numbers 

 of colonies in the new race, and none in the check. One of 

 these two had been kept at 40° C. to 44° C. for twenty-seven 

 days, the other under the same conditions for one month. 



