SYMPTOMATIC ANTHRAX. 169 



can not be cultivated in an atmosphere of oxygen. It is 

 purely anaerobic, and does not grow in an atmosphere of car- 

 bonic acid gas. 



It grows best when glucose (1.5 to 2 per cent.) or glyc- 

 erin (4 to 5 per cent.) is added to the culture-medium. It 

 grows in all media. It liquefies gelatin. It grows best 

 at the temperature of the incubator, 37 C., but does not 

 grow at a temperature below 14 C. In deep-seated punct- 

 ures of gelatin or agar it grows in three or four days, and 

 produces during its growth gas bubbles. The colonies appear 

 as globules which cause liquefaction of the gelatin and 

 coalesce into irregular tabulated liquid areas. The dried 

 spores retain their vitality for months. They resist a tem- 

 perature of 80 C. for one hour, but five minutes' exposure 

 at 100 C. is sufficient to destroy them. Carbolic acid 

 (5 per cent.) is not effective as a disinfectant in less than ten 

 hours. The vegetative form, however, is killed in from three 

 to five minutes. Bichloride of mercury (1 : 1000) will kill 

 the spores in two hours. 



Pathogenesis. Cattle, sheep, goats, guinea-pigs, and mice 

 -are susceptible animals. Horses, asses, and rats show only 

 slight local swelling, but no general infection. Dogs, cats, 

 rabbits, chickens, pigeons, and hogs are immune. Inocula- 

 tions are generally made deep into the subcutaneous tissue 

 either with pure cultures of the microorganisms or from bits 

 of tissue of a suspected animal. The symptoms are a rise of 

 temperature, followed by painful swelling at the point of 

 inoculation. Death takes place in from one to two days. 

 The autopsy reveals an extensive swelling of the subcutane- 

 ous tissues with emphysema. The cedematous fluid is blood- 

 stained, and the muscles are dark and prominent. The 

 lymphatic glands are involved. The internal organs show 

 little change. In the fluid of the oedema the bacilli are found 

 in large numbers, lying singly. Early autopsy reveals no 

 bacteria in the blood, only a few in the internal organs. 

 Late autopsy shows a considerable quantity of organisms that 

 have invaded the whole body. The bacilli in the body are 

 found to contain spores. This serves as a differentiation, 



