236 MICROBIOLOGY 



will grow on these media when inoculated directly from 

 glanders tissue. Its most characteristic growth seems to ap- 

 pear on potato. In isolating this organism from glandered 

 organs acid-glycerine-agar and potato are the culture media 

 that give the most constant and satisfactory results. 



Agar. On agar, yellowish white, at first transparent, but 

 later somewhat opaque .colonies, appear after twenty- four 

 hours. The colonies are round, with an even margin, and 

 under low magnification the surface is seen to be finely granu- 

 lar. In older cultures, the colonies become more or less yellow. 

 These characteristics are more pronounced on acid-glycerine- 

 agar. 



Gelatin. On this medium it grows slowly at room tem- 

 perature. The growth is of a grayish w r hite color and becomes 

 abundant. The gelatin is not liquefied. 



Potato. Potatoes that are too acid should not be used. 

 On those that are less so, the growth is quite vigorous and 

 within forty-eight hours covers the surface with a yellowish, 

 transparent, slimy layer. It grows darker until it becomes a 

 deep reddish brown hue. 



Serum. Upon serum it develops small, clear, transparent, 

 drop-like colonies. 



Bouillon. In bouillon the liquid becomes uniformly 

 cloudy. A ropy viscid sediment is formed. A slimy pellicle 

 appears after some days. The culture liquid becomes darker 

 by standing. In acid glycerine bouillon, growth is more 

 vigorous, but otherwise does not differ from that in bouillon. 

 It does not act on the sugars. 



Milk. Milk is coagulated very slowly with the produc- 

 tion of acid. 



Life conditions and properties. Bacterium mallei is 

 aerobic. It exhibits Brownian movement to such a marked 

 degree that the mistake of considering it motile has frequently 

 been made. Its most favorable temperature for cultivation is 

 37 C. Development takes place slowly, at room temperature 

 and ceases at a temperature of 43 C. It imparts to the liquid 

 in which it grows a specific toxin a substance which consti- 



