Report on the Bacteriology of Water. 



437 



the food-material has not degenerated in quality during the interval 

 of nearly a month, for it had remained in the flask for that interval. 

 From 6.15 onwards the above filament was segmented into a short 

 and a long segment; in the following table I resume the further 

 growth of the shorter one. 



Here the doubling : 



65130 /x = 6.15 P.M. 7.23 P.M. = 68 min. at 19 '25 19 '5 19 -0C. 



At 8.15 another segment in the same drop was chosen, and measured 

 as follows : 



Some interesting comparisons are possible here. For instance, the 

 original filament was 65 /t long at 4.3 P.M., and it was 109 p. long at 

 4.54 P.M. ; the present segment was 65 ft long at 6.15, and was 109 /t 

 long at 7.6. In both cases, therefore, exactly the same time, i.e., 

 fifty-one minutes, was occupied in growing the 44 ft referred to, in 

 the first case the temperature being 19 to 18'9 C., and in the second 

 19-25 19-5 19 C. 



Then, again, the doubling period is the same as the second one of 

 the original filament, viz., sixty-eight minutes, at nearly the same 

 temperature. 



Here the doubling period is becoming extended to more than 

 double the previous ones, indicating the spoiling of the drop either 



