348 IVAN C. HALL 



The usual control tests failed to show contamination in any 

 tube so that the above result demonstrates that growth is possible 

 without added glucose but is not so good as with it. 



That a modicum of carbohydrate is necessary is indicated 

 by a lot of media made as usual with the exception of added 

 glucose and from which only a portion^ of the tissue carbohydrates 

 had been removed by the growth of B. communior, in which 

 no growth of gonococci could be secured. But media which 

 had been so fermented and then re-inforced by addition of 1 

 to 2 per cent glucose yielded very excellent growth showing that 

 inhibition in the fermented media could scarcely have been 

 due to the accumulation of metabolic wastes from B. communior. 

 Thus it was shown that for these strains the order of preference 

 for added glucose content in media previously fermented by 

 B. communior is 1 per cent, 2 per cent, and 3 per cent. Since, 

 however, I have found no advantage in a prehminary fermenta- 

 tion the addition of 0.5 per cent glucose to unfermented media 

 has been retained. 



PHOSPHATES 



The use of unsaturated phosphates in culture media for bac- 

 teria was recommended by Henderson and Webster (1907) 

 for their stabiUzing effect upon the reaction, and a medium of 

 this sort plus human serum was advocated by Martin (1911) 

 for the cultivation of the gonococcus. 



My experiments upon the necessity of added phosphate have 

 been inconclusive; at times excellent growth has been secured 

 without its addition. In three separate double lots of testicular 

 infusion agar made with and without the addition of inorganic 

 phosphate the advantage has been in favor of that containing 

 it. I have made no effort to determine the optimum amount 

 or to attempt the cultivation of gonococcus in phosphate free 

 media. 



' That the tissue sugar was not completely eliminated was proven by further 

 gas production in deep tubes of the supposedly sugar free testicular infusion 

 agar by B. communior. 



