H. B. Hutchinson and J. Clayton 1.")7 



Tablk 1. 



(Iroirtli ofH. cytophaga in Peptone Solution with Cellulose. 



Concentration of Peptone Solution (per cent.) 



, - -^ ^ 



00001 0001 001 01 10 



Growth ... ... ++ +^ T-+ ++ - 



Tablk II. 



Groui/i of 8. cytophaga in Peptone Solution with and 



without Cellulose. 



(Jrowth after Concentration of Peptone Solution (per cent.) 



8 (lays I * \ 



— 000,-> 0010 0025 0050 010 0-25 0-50 1-0 



Without cellulose - - - - _____ 



With cellulose and 



ammoniuui salts + + + + + + + + + + + + + + + + + + + + -+ - 



The unsuitabiUty of peptone as the sole nutrient is well brought out, 

 the organism failing to show growth in any of the various concentrations 

 tested. In the presence of filter paper strong growth occurred up to 

 the 0-025 per cent., but marked inhibition set in with 0-25 per cent. 

 solution. 



Comparison of simpler nitrogen compounds. Throughout the cultural 

 work in connection with <S'. cytophaga the superior value of inorganic 

 forms of nitrogen has been well demonstrated, and a comparison of 

 these is afforded by Table III. Proceeding from a basis of normal mineral 

 salt solution and filter paper, tests were made with increasing amounts 

 of sodium ammonium phosphate, ammonium phosphate, sodium nitrite 

 and sodium nitrate. 



Table III. 

 The Relative Value of Inorganic Nitrogen Compounds. 



Concentration of salt solution (per cent.) 



The results obtained after three days' incubation were on the whole 

 similar to those given above, except that with longer incubation the 

 growth was stronger and that the critical concentration showed a 

 general displacement to the higher levels. It may be assumed that the 



