470 C. P. FITCH AND W. A. BILLINGS 



The bubble, or the small amount of gas, encountered so often in our 

 fermentation tests with Bacillus abortivo-equinus in lactose and sac- 

 charose broth is not of physical, but of chemical, origin. 



Bacillus abortivo-equinus produced approximately 2 per cent gas in 

 lactose in 80 per cent of 116 trials, and in saccharose slightly less than 

 2 per cent gas in 50 per cent of 56 trials. 



Bacillus abortivo-equinus may or may not produce gas in 1 per cent 

 lactose or saccharose broth, even varying in this respect in duplicate 

 and triplicate tests. 



Bacillus abortivo-equinus possesses as an original physiologic char- 

 acteristic the ability, in most cases, to ferment lactose to a small extent, 

 and also, in some cases, to ferment saccharose to a less extent. This 

 characteristic in all probability has not as yet been accentuated by 

 environment. 



In these tests the four strains of B. abortivo-equinus produced the 

 following average percentages of gas in the carbohydrates which were 

 fermented: xylose 51 per cent; raffinose 39 per cent; arabinose 59 per 

 cent; sorbite 82 per cent; dulcite 95 per cent; glucose 74 per cent; man- 

 nite 81 per cent. 



De Jong as a result of his original observations states that the 

 germ which he isolated from the uterine exudate of mares which 

 aborted does not form gas in lactose but does in sucrose. In an 

 inaugural dissertation published later Van Heelsbergen working 

 in the same laboratory as De Jong makes the positive statement 

 that Bad. abortivo-equinus does not ferment either lactose or 

 sucrose. 



Meyer and Boerner state that B. abortivo-eqinus does not fer- 

 ment either lactose or sucrose. 



Mudge found that heating in streaming steam seems to hy- 

 drolyze lactose and maltose and by sterilizing by filtration this 

 hydrolysis can be avoided. 



The study here reported was begun three years ago but owing 

 to the fact that we w T ere unable to obtain certain of the carbohy- 

 drates the work was very much delayed. The media used were 

 prepared from lean beef, following the ordinary method. The 

 muscle sugar was removed by the use of Bad. coli and then tested 

 to insure that it was sugar free. One per cent of the various 

 carbohydrates was added to this sugar free infusion bouillon. 



