VIBRIO PROTEUS. 361 



or less sharply defined. (See Fig. 69, a.) At times 

 they may show indefinite markings or creases, somewhat 

 suggestive of lobulations. After forty-eight hours on 

 gelatin they usually range from one to three millimetres 

 (some even larger) in diameter, and will appear as 

 sharply cut, saucer-shaped pits of liquefaction, in the 

 most dependent portion of which lies a dense, irregular 

 mass, the colony proper. Under low magnifying power 

 they present at this stage an appearance similar to that 

 shown in Fig. 69, b, the central dense mass representing 



FIG. 69. 



am 



Colonies of the Fiiikler-Prior bacillus on gelatin, x about 75 diameters, 

 a. After twenty-two hours at 20 to 22 C. 6. After forty-eight hours at 20 



to 22 C. 



the colony and the irregular ragged lines surrounding it 

 being shreds that have become torn away as it sank into 

 the liquid caused by its growth. The zone surrounding 

 it, extending to the periphery, is somewhat cloudy, and 

 is simply liquefied gelatin. There is a marked tendency 

 for the liquefaction to spread laterally and for the 

 colonies to run together, so that, even on plates con- 

 taining few colonies, in sixty to seventy-two hours at 



