xii] PATHOGENIC BACILLI ; GROUP C 263 



as well as of glycerine Agar tubes set with slanting surface) 

 show, in the course of one or two days, a copious floccular 

 or granular whitish precipitate, the condensation water 

 itself remaining limpid. The amount of this precipitate 

 increases till about the fifth or seventh day, when it has 

 reached its maximum. 



Agar tubes inoculated with the influenza bacillus support 

 life in the organism longer than broth tubes, particularly if 

 the Agar tubes be inoculated by stab-culture. We have 

 successfully carried on sub-cultures from Agar cultures 

 through many generations, in fact we have some cases 

 that have reached already the twentieth generation, and 

 we see no reason why there should be any hmit 

 placed at all, provided each successive sub-culture be 

 established within a week — after that time the result 

 becomes uncertain. 1 But if the culture tube after five or 

 six days' incubation at 37° C. be then kept at the ordinary 

 temperature (capped and protected from drying) the life of 

 the culture can be preserved for a much longer time ; we 

 have as a matter of fact found it living after two weeks ; 

 this would certainly not have been the case if any culture 

 of the series had been kept at 37" C. for a fortnight. 



3. Culture on potato. — No visible growth is to be obtained. 



The vitality of the cultures is considerably prolonged if 

 nutrient gelatine after inoculation is incubated at 37° C. ; 

 herein good growth occurs, and the growth remains alive for 

 at least three to four weeks. 



' We add here that under the above conditions we have carried on 

 the sub-cultures on Agar from the sputum through more than thirty 

 generations. 



