362 BACTERIOLOOr. 



ular, whitish mass, which is more or less limited to the 

 point of inoculation. On potato, at the temperature of 

 the incubator, its spore-formation may easily be ob- 

 served. 



Stab and Slant Cultures. — Stab and slant cul- 

 tures on agar-agar present in general the appearances 

 given for the colonies, except that the growth is much 

 more extensive. The growth is always more pro- 

 nounced on the surface than down the track of the 

 needle. 



On gelatin it causes liquefaction, which begins on the 

 surface at the point inoculated, and spreads outward 

 and downward. 



It grows best with access to oxygen, and very poorly 

 when the supply of oxygen is interfered with. 



Under favorable conditions of aeration, nutrition, 

 and temperature its growth is rapid. 



Under 12° C. and above 45° C. no growth occurs. 

 The temperature of the body is most favorable to its 

 development. 



The spores of the anthrax bacillus are very resistant 

 to heat, though the degree of resistance is seen to vary 

 with spores of different origin. Esmarch found that 

 anthrax spores from some sources would readily be killed 

 by an exposure of one minute to the temperature of 

 steam, whereas those from other sources resisted this 

 temperature for longer times, reaching in some cases 

 as long as twelve minutes. 



Staining. — The anthrax bacilli stain readily with 

 the ordinary aniline dyes. In tissues their presence 

 may also be demonstrated by the ordinary aniline stain- 

 ing fluids, or by Gram's method. They may also be 

 stained in tissues with a strong watery solution of dahlia. 



