BACILLUS OF MALIGNANT (EDEMA. 405 



radiating stripes, easily to be detected with the aid of 

 a small hand-lens. In deep-stab cultures in agar-agar 

 and gelatin, development only occurs along the track of 

 puncture at a distance below the surface. Growth is 

 frequently accompanied by the production of gas-bubbles. 



It causes rapid liquefaction of blood-serum with pro- 

 duction of gas-bubbles, and in two or three days the 

 entire medium may have become converted into a yel- 

 lowish, semi-fluid mass. 



The most satisfactory results in the study of the 

 colonies are obtained by the use of plates of nutrient 

 agar-agar, kept in a chamber in which all oxygen has 

 been replaced, by hydrogen. The colonies appear as 

 dull-whitish points, irregular in outline, and when 

 viewed with a low-power lens are seen to be marked 

 by a network of branching and interlacing lines that 

 radiate in an irregular way from the centre toward the 

 periphery. 



It grows well at the ordinary temperature of the 

 room, but reaches its highest development at the tem- 

 perature of the body. 



It stains readily with the ordinary aniline dyes. It 

 is decolorized when treated by Gram's method. 



Pathogenesis. The animals that are known to be 

 susceptible to inoculation with this organism are man, 

 horses, calves, dogs, goats, sheep, pigs, chickens, pigeons, 

 rabbits, guinea-pigs, and mice. Cases are recorded in 

 which men and horses have developed the disease after 

 injuries, doubtless due to the introduction into the 

 wound, at the time, of soil or dust containing the 

 organism. 



If one introduce into a pocket beneath the skin of a 

 susceptible animal about as much garden earth as can 



18* 



