I>I>CKMTIMN 



8PE( IBS. 



585 



On potato a similar colour is 

 produced. 



They were isolated from nasal 

 mucus. 



Bacillus subflavus (Zimrner- 

 niann). Rods 1*5 to H p. in length, 

 77 /i in width, and in chains. Motile. 



Colonies prominent, yellowish- 

 white. 



On the surface of gelatine they 

 form a yellowish-grey layer, and 

 on the surface of agar and potato 

 the growth is yellow. 



They occur in water. 



Bacillus subtilis (Hay bacillus). 

 Cylindrical rods as much as 6 n 

 in length. Single forms grow to 

 double their length, and then 

 undergo division. They also form 

 threads which may be composed of 



FIG. 211. BACILLUS SUBTILI* WITH 

 SPORES (BAUMGAKTKX). 



long rods, short rods, and cocci. 

 They are motile, and provided with 

 a flagellum at each end. If the 

 nourishing medium is impoverished, 

 the multiplication of the rods by 

 division gradually ceases, and spore- 

 formation commences. The rods 

 become motionless, and a dark- spot 

 is visible, either in the middle or 

 towards one end. This gradually 

 develops into a shining spore with 

 a dark outline. The rods swell 

 slightly during this process ; then- 

 contour becomes undefined, and 

 soon disappears entirely : spores 

 being set free in about twenty- 

 four hours. The spores are I"J p. 

 long, and -6 p broad. They develop 

 into rods in the following way :- 

 On one side of the spore a swell] 

 appears, at the summit of which 

 an opening in the spore-meml 

 results, and the germ tin- 



lengthens into a rod, and remains 

 for a time attached to the empty i 

 spore-membrane. 



The 8jx)res are widely distributed, 

 and occur in the air. nil 

 On the excren >rous 



animals the bacilli form ;i 

 efflorescence, and a thirk crumpled 

 skin on liquid manure. 



They flourish equally in liquids 

 and upon damp, solid, noun-hiiii: 

 media. They are aerobic : <K j 

 tion of oxygen causes the growth 

 of the bacilli to cease, and the 

 degenerate. 



In plate-cultivations the colonies 

 are white, and, under a low power, 

 granular and irregular in outline 

 and faintly-green i si i. Liquefaction 

 in, producing <i like 



saucers. The centre i- opaque 

 is surrounded by a network of 

 filaments, which extend into tin 

 gelatine surrounding the colon 





Inoculated in the depth f gela- 

 tine, liquefaction 00 

 the tra.-k of the Modi*, MM a him 



