PLATE IV. 



Saccharomyces anomalus. 

 Figure 1.— Colonies of the parent type in glucose gelatin. 

 Figure 2. —Colonies of a new race grown under the same conditions. 

 The new race colonies show a ragged outline, due to the outgrowth of elon- 

 gated cells. 



Bacillus coli communis. 



Figure 3. —Colony of the parent type, grown in gelatin. 



Figure 4.— A colony of the new race A, grown under like conditions. 



