SPECIES DESCRIBED BY VARIOUS WRITERS. 2O3 



posed to the air various bacilli are found to develop. 



One of these has a perfectly characteristic appear- 



ance on cultivation. In plate culti- 



vations it causes a cloudy growth, 



spreading from various points ; if a 



cover-glass impression is made, this is 



found to consist of parallel rods, vary- 



ing in length. The chains of rods be- 



come twisted at intervals into curious 



convolutions, from which offshoots are 



continued in various directions. 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 



bacillus forms on the surface visible 



windings, from which fine filaments grow 



down into the gelatine. It spreads out 



also in almost parallel lines transversely 



from the needle track. On an oblique 



surface of nutrient agar-agar the fila- 



ments spread downwards into the sub- 



stance of the jelly, and outwards from 



the central streak on the surface, forming 



a feather-like cultivation * (Fig. 40). 



Bacillus valei, Cheshire and 

 Cheyne.t Rods varying in size, and 



FIG. 40. 



PURE CULTI- 

 VATION 



OF BACILLUS 



FIGURANS IN 



* Crookshank, Notes from a Bacteriolog. Laboratory. Lancet, 

 1885. 



t Cheshire and Cheyne, Journ. Royal Microscopical Society, 

 1885, pp. 582-601. 



