400 L. D. BUSHNELL 



produced and there was clear e\adenee that the organisms at- 

 tacked the glycerol. There seemed to be vigorous growth in 

 inulin-peptone solution but the action upon the medium was not 

 so vigorous. 



The proteolytic action of these organisms is also shown by 

 the production of ammonia from asparagus, alkaline egg medium 

 and whole milk. 



Amino-acids. In the Uberation of amino-acids from the pep- 

 tone solution plus carbohydrates there is a correlation similar to 

 that seen in the production of ammonia from similar solutions. 

 From peptone alone there is a marked decrease in the amino-acid 

 content after the first three days. 



The freeing of amino-acids does not correspond to the ease with 

 which a carbohydrate is fermented. There is an increase in the 

 amino-acid content for a certain period in all cultures. In the 

 presence of glucose, salicin, sucrose, starch and inulin this increase 

 continues to the close of the experiment. With lactose and gh'c- 

 erol there is a slight decrease as the culture ages. In case of 

 mannitol there is a decrease from the beginning. There is a 

 marked production of amino acids from asparagus, alkaline egg 

 medium, and whole milk. In a purely nitrogenous media there is 

 a marked increase in the amino-acid nitrogen, followed by a de- 

 crease as seen in alkaUne egg and peptone solutions. TMs point 

 is not so marked in media containing fermentable compounds 

 such as asparagus, milk, glucose, salicine, glycerol and starch 

 solutions. Apparently the organisms may not attack the amino- 

 acids as readily in the presence of fermentable carbohydrates as 

 they do in their absence, or they may be produced more rapidly 

 than they are used and thus accumulate in the medium. It is 

 impossible to elucidate this point at present since total nitrogen 

 determinations were not made on each sample at various periods. 



Volatile fatty acids. Fairly large amounts of volatile fatty 

 acids were produced in most cases. The figures in table 4 rep- 

 resent cubic centimeters of N/20 alkali used to neutralize the 

 acid obtained by complete distillation, as above described. The 

 per cent of volatile acid in each fraction was obtained by dividing 

 the amount by the total acid. Usually there was a change in the 



