Report on the Bacteriology of Water. 



299 



Here we see growth going on at the enormous rate, hardly measur- 

 able, of 15 fi per minute. In such cases the growing tip is seen 

 moving almost like an Oscillatoria. 



Then the filament suddenly contracted and broke up, and in a 

 short time presented the granular appearance of dead cells. 



The following measurements under the l/12th immersion were 

 made on a germinal filament which had emerged from the spore 

 during the night. The culture in broth was exposed to the day- 

 light the whole time,* but the sun was obscured by haze and 

 clouds. The temperature was rising slowly from 18 to 21 C., 

 alco during the whole period observed. 



Each division of the micrometer scale was in this case again 

 equal to T82 ft, and the measurements were made as 1, 2, 3, or 4 

 divisions were travelled over. 



Here we have a total growth of the young filament amounting 

 to 47'22 fi in 120 minutes, which would give an average rate of nearly 



* It should be noted that in these high-power observations a bright illuniinatiou 

 has of course to be employed. 



Y 2 



