48 



was not counted. General fusion of colonies. 



In the above results the round white colonies varied from 

 approximately ^th" to Jth" in diameter, the small red from 

 approximately ^2^^" ^o i^^h", and the large re(i from ^V^^' 

 to X6*h"- '"^ome of the large red colonies tended towards a 

 paler shade, almost a pink, while the small red were a deep 

 red surrounded by a rosy halation. The white colonies 

 without exception had a small red centre. After 24 hours' 

 incubation, the plates showed a large number of microscopic 

 red points, which resolved themselves into the usual small 

 red colonies. The results of incubation of the Bile .Salt 

 lactose litmus broth were as follows : — 



I. — This tube after 24 hours shoAved an acid re- 

 action and was gassing freely. This contained -gtroth 

 part of a mussel. 



II. — This tube after 48 hours sho\\ed a slight acid 

 reaction, but no further change after prolonged in- 

 cubation. This tube contained g(,;,i55th part of a nnissel. 



III. and IV. showed no reaction, even after pro- 

 longed incubation. 



As a result of these tests and the consequent evidence of 

 the presence of the Bacilhis coli group of organisms, it Avas 



