158 EOYAL SOCIETY OF CANADA 



The following diagrams illustrate these differences 



/ 



The probable explanation of these differences between submerged 

 and surface colonies is that the same amount of enzyme works in a 

 smaller area, in the case of the former colonies. The amount of 

 glucoside available is also greater in the case of the submerged colony. 



In thin layers the colour of the sesculetin iron is brown — 

 between Latericius and Badius of Saccardo, (2) and in some in- 

 stances as light in colour as Isabellinus. 



Another point investigated was the effect of Liebig's meat 

 extract when used for the preparation of aesculin media. Liebig's 

 meat extract contains a certain amount of glycogen, and it is well 

 known that sugars at times interfere with enzyme reaction, for the 

 only advantage bacteria can obtain from the splitting of glucosides 

 is the formation of carbohydrates, which they need for food. When 



