[BERKELEY] MARINE BACTERIA 25 



The following table illustrates schematically the results obtained 

 in each series at the periodic tests. Where O is inserted in the table 

 it indicates that there was no evidence of growth in the culture, and 

 it was therefore not tested, + indicates a positive reaction, — a negative 

 one. Whenever the nitrite test gave a negative result the culture was 

 tested for nitrate which was invariably found. 



