SYSTEMATIC AND DESCRIPTIVE. 



ance. They can be cultivated on nutrient agar- 

 agar and nutrient gelatine. The latter is slowly 

 liquefied, but the appearances are not characteristic. 

 Spore-formation occurs in the usual f F^\ 

 way (Fig. 120). It was first observed 

 on boiled cabbage. 



Bacillus figurans (Wurzel Ba- 

 cillus 'j Bacillus my co ides, Fliigge). 

 Rods, with rounded ends, varying in 

 length. Spore-formation present. In 

 plate-cultivations they cause a cloudy 

 growth, spreading from various points; 

 if a cover-glass impression is made, 

 this is found to consist of the regularly- 

 arranged parallel rods. The chains of 

 rods become twisted at intervals into 

 curious convolutions, from which off- 

 shoots are continued in various direc- 

 tions. These long shoots or processes 

 are again twisted at intervals into 

 varying shapes and patterns (Plate 

 XXV., Figs, i and 2). Cultivated in 

 nutrient gelatine, the bacilli form on 

 the surface visible windings, from 

 which fine filaments grow down into 

 the gelatine. They spread out also in PURE CULTIVA- 



J r TION OF BACIL- 



almost parallel lines transversely from LUS FIGURANS 



IN NUTRIENT 



the needle track. On an oblique sur- AGAR-AGAR. 

 face of nutrient agar-agar the filaments spread 

 downwards into the substance of the jelly, and 



FIG. 121. 



