374 



[Vol. 9 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



being agitated (see pi. 29, fig. 1). No gas was produced in the 

 closed arm in any of the substances listed in contrast to Bacillus 

 Coli which showed abundant gas in a number of the solutions. 

 This does not mean that no gas was produced; it has already 

 been shown that ammonia was produced in nutrient broth, but 

 that because of the growth being limited to the open arm, any 

 gas which was produced, and which in this organism must not 

 be noticeable, passed off into the atmosphere through the open 

 arm. However, no carbon-dioxide or hydrogen has ever been 

 collected and it is not likely that they were formed in any appre- 

 ciable quantity in this organism since it is not an acid producer. 



Acid production. — Various experiments indicate that this or- 

 ganism does not produce acid in any of the ordinary 



media. 



It 



has already been noted that in acid broths the m< hum changes 

 toward neutrality or becomes alkaline and that litmus milk be- 

 comes blue. Likewise, in the presence of carbohydrates there is 

 no acid production at any time during the growth period. The 

 following experiments illustrate this. Litmus agars containing 

 no other nutrients than 1 per cent of the following carbohydrates 

 remained blue for 2 months, showing no pinkish tinge at any 

 time: dextrose, galactose, mannite, lactose, saccharose, raffinose, 

 and glycerin. Nutrient agar with brom cresolpurple as indicator 

 containing 1 per cent of the following: dextrose, galactose, lac- 

 tose, and saccharose showed no trace of yellow in 10 days' growth. 



Lactose agar stabs with Andrade-Penny's indicator (Holman, II, 



'1 1-) showed no color, in contrast to Bacillus Coli which developed 

 a conspicuous pink color in 48 hours. Instead of producing acid 

 this organism produced alkali in the presence of carbohydrates 

 as is shown in the following table. The media consisted of nu- 

 trient broth plus 1 per cent of each of the carbohydrates listed. 





TABLE VIII 







Type of carbohydrate 



Original J'h 



Th :it end 



Fh fit <"d 





<^ 



of 5 days 



of 10 davs 



Dextrose 



7.2 



7.2 



7.3 



Levulose 



7.2 



7.2 



7.4 



Mannite 



7.2 



7.4 



7.4 



Lactose 



7.2 



8.0 



8.2 



Maltose 



7.2 



8.0 



8.0 



Saccharose 



7.2 



8.0 



8.2 



Glycerin 



7.2 



7.2 



7.2 



Broth (without carbohydrate) 



7.2 



8.0 



8.0 



