Report on the Bacteriology of Water. 



317 



Relative Growths of Germinating Filaments in Darkness and in 

 various Coloured Lights. 



920 

 900 

 60 

 60 

 40 



tzo 



00 

 180 

 160 

 140 



120 



// 



~4pjn 5 



7 8 9 10 II 



On comparing this table and curves with those last discussed, we 

 find the following facts come out : 



The retarding action behind the blue and ordinary glass screens is 

 much more marked, simply, no doubt, because the insolation was 

 more intense. During the whole period (from 12 noon to 10.30 P.M.) 

 of 10| hours, although the time of exposure to light was shorter by 



