PLATE II. 



FIG. i. Bacterium indicum. 



Micrococcus indicus. 



Bacillus indicus. 



Tube inoculated from a nutrient agar-agar plate- 

 cultivation. By plate-cultivation, or by successive 

 cultivation on potatoes, a pure cultivation can be 

 obtained. The growth has then the colour of red 

 sealing-wax, and a peculiar crinkled appearance. 

 After some days the growth loses its bright 

 colour, and becomes purplish like an old cultiva- 

 tion of Bacterium prodigiosum. 



FIG. 2. Bacillus cyanogenus. 



Bacterium syncyanum. 

 Bacillus of blue milk. 



Tube inoculated from a potato-cultivation. The bacillus 

 forms a whitish layer, and colours the nutrient 

 agar-agar a smoky brown. 



FIG. 3. Bacterium prodigiosum. 



Monas prodigiosa. 



Micrococcus prodigiosus. 



Bacillus prodigiosus. 



Blood rain. 



Tube inoculated from a potato cultivation. The bacterium 

 grows very rapidly, forming a blood-red growth, 

 which gradually acquires a purplish colour. 



