482 Profs. Percy Franklaiid and Marshall Ward. 



Thus in the steam-sterilised L. Katrine water, the B. coli communis 

 disappeared in a surprisingly short time, being no longer demonstrable 

 on the Ylth day after infection. In this case also the decline was more 

 rapid in the water kept at a summer than in that at a winter tempera- 

 ture. 



Very similar again was the behaviour of the B. coli communis in. 

 the L. Katrine water previously sterilised Iby filtration through 

 porous porcelain, thus : 



