BACTERIA PATHOGENIC IN ANIMALS. 235 



teria cells by means of a method of contrast staining ; 

 hence in this respect they behave like spores. Still 

 their germination has not yet been observed, on which 

 account their nature cannot be definitely determined. 



The glanders bacilli cannot very well be cultivated 

 on gelatine, for they can only grow at a temperature 

 at which it begins to be liquefied. Nutrient agar- 

 agar must therefore be used, to which 3 to 4 per 

 cent, of glycerine may with advantage be added. If 

 the agar-agar plates are kept for two days in the 

 incubator at a temperature of 37°, the colonies are 

 distinctly to be seen. Small, round, dirty-white flakes 

 are formed, which are distinctly translucent at the 

 edges, and quite bright on the surface. With a low 

 power the colonies are seen to have sharp edges and a 

 very slightly granular surface. On stroke cultivations 

 in glycerine agar-agar, a dirty white, slimy, translucent 

 coating is formed. The culture on blood serum is 

 almost transparent and slightly yellow in colour ; 

 generally round the edges of the stroke culture in 

 this medium a few free colonies occur, which either 

 remain permanently isolated, or coalesce at a few 

 places on the circumference. The growth of the 

 glanders bacillus upon potatoes is especially character- 

 istic ; if the preparation is kept at blood heat, a very 

 luxurious growth takes place. Along the inoculation 

 stroke a slimy coating appears, which at first is 

 yellowish and almost transparent, but which becomes 



