DESCRIPTION OF PLATE II. 

 Pure-cultivations of Bacteria. 



Fig. 1. — In the depth of Nutrient Gelatine. A pure-cultivation of Kochs 

 comma-bacillus (Spirillum cholerse AsiaticEe) showing in the track of 

 the needle a funnel-shaped area of liquefaction enclosing an air-bubble, 

 and a white thread. Similar appearances are produced in cultivations of 

 the comma-bacillus of MetchnikofE. 



Fig. 2. — On the surface of Nutrient Gelatine. A pure-cultivation of Bacillus 

 typhosus on the surface of obliquely solidified nutrient gelatine. 



Fig. 3. — On the surface of Nutrient Agar-agar. Pure-cultivation of Bacillus 

 indicus on the surface of obliquely solidified nutrient agar-agar. The 

 growth has the colour of red sealing-wax, and a peculiar crinkled 

 appearance. After some days it loses its bright colour and becomes 

 purplish, like an old cultivation of Micrococcus prodigiosus. 



Fig. 4. — On the surface of Nutrient Agar-agar. A pure-cultivation obtained 

 from an abscess (Staphylococcus pyogenes aureus). 



Fig. 5. — On the surface of Nutrient Agar-agar. A pure-cultivation obtained 

 from green pus (Bacillus pyocyaneus). Thfe growth forms a whitish, 

 transparent layer, conlposed of slender bacilli, and the green pigment 

 is diffused throughout the nutrient jelly. ' The growth appears green by 

 transmitted light, owing to the colour of the jelly behind it. 



KiG. H.— On tJie surface of Potato. A pure-cultivation of the bacillus of 

 glanders on the surface of sterilised potato. 



