554 BACTERIOLOGY. 



Bacilli containing spores are usually clubbed or spin- 

 dle shape. 



This bacillus stains readily with the ordinary aniline 

 dyes. It is decolorized by Gram's method. Its spores 

 may be stained by the methods usually employed in 

 spore-staining. 



PATHOGENESIS. When susceptible animals, especi- 

 ally guinea-pigs, are inoculated in the deeper subcutane- 

 ous cellular tissues with pure cultures of this organism, 

 or with bits of tissue from the affected area of another 

 animal dead of the disease, death ensues in from one to 

 two days. It is preceded by rise of temperature, loss 

 of appetite, and general indisposition. The site of 

 inoculation is swollen and painful, and drops of bloody 

 serum may sometimes be seen exuding from it. At 

 autopsy the subcutaneous cellular tissues and under- 

 lying muscles present a condition of emphysema and 

 extreme oedema. The oedematous fluid is often blood- 

 stained and the muscles are of a blackish or blackish- 

 brown color. The lymphatic glands are markedly 

 hypersemic. The internal viscera present but little 

 alteration visible to the naked eye. In the blood- 

 stained serous fluid about the point of inoculation short 

 bacilli are present in large numbers. These often pre- 

 sent slight swellings at the middle or near the end. 

 They are not seen as threads, but lie singly in the 

 tissues. Occasionally two will be seen joined end to 

 end. If the autopsy be made immediately after death, 

 these organisms may not be detected in the internal 

 organs ; but if not made until after a few hours, they 

 will be found there also. In recent autopsies only vege- 

 tative forms of the organism may be found ; but later 

 (in from twenty to twenty-four hours) spore-bearing rods 



