394 APPLICATION OF METHODS OF BACTERIOLOGY 



36 and 39 C. Its colonies on glycerin-agar-agar and on 

 coagulated blood-serum are described as iridescent, trans- 

 parent, and whitish. On gelatin at 18-20 C. it develops 

 as small, sharply defined, white colonies without liquefaction 

 of the medium. In stab-cultures it develops both on the 

 surface and along the track of the needle. Its growth is 

 slow. It does not cause a diffuse clouding of bouillon, but 

 grows rather as irregular, flocculent clumps that adhere to 

 the sides or sink to the bottom of the vessel, leaving the fluid 

 clear. It shows but limited growth on potato. It does not 

 ferment glucose with production of gas, nor does it form 

 indol. It coagulates milk. 



This organism is killed by drying at ordinary room-tem- 

 perature in four days. It is killed in three or four hours 

 by direct sunlight. It is destroyed in a half hour by 80 

 C., and in a few minutes by 100 C. (steam). It is killed in 

 one hour by 1 per cent, carbolic acid and in two hours by 

 1 per cent, milk of lime. 1 



It is pathogenic for rats, mice, guinea-pigs, ground squir- 

 rels, rabbits, hogs, horses, monkeys, cats, chickens, and 

 sparrows. Pigeons, hedgehogs, and frogs are immune, and 

 dogs and bovines are apparently so. 2 



Animals succumb to subcutaneous inoculation in from two 

 to three days. According to Yersin, the site of subcutaneous 

 inoculation becomes edematous and the neighboring lym- 

 phatics are enlarged in a few hours. After twenty-four hours 

 the animal is quiet, the hair is rumpled, tears stream from the 

 eyes, and later convulsions set in, which last till death. The 



1 See Viability of the Bacillus Pestis, by M. J. Rosenau, U. S. Marine- 

 Hospital Service, Bulletin No. 4, of the Hygienic Laboratory, U. S. M.-H., 

 Washington, D. C., 1901. 



J Nuttall, Centralblatt fiir Bakteriologie und Parasitenkunde, 1897, 

 Abt. 1, Bd. xxii, S. 97. 



