598 APPLICATION OF METHODS OF BACTERIOLOGY 



ten hours, whereas the vegetative forms are destroyed in 

 from three to five minutes; in corrosive subhmate solution 

 of the strength of 1 : 1000 the spores are killed in two hours. 



When gelatin cultures are examined microscopically the 

 organisms are usually seen as single rods with rounded ends. 

 When cultivated in agar-agar at a higher temperature 

 spores are formed after a short time; the spores are oval, 

 slightly flattened on their sides, thicker than the bacilli, 

 and, as stated, frequently occupy a position inclining to 

 one of the poles of the bacillus, though they are as often 

 seen in the middle. 



Bacilli containing spores are usually clubbed or spindle 

 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, especially 

 guinea-pigs, are inoculated in the deeper subcutaneous 

 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 underlying muscles present a condition of 

 emphysema and extreme edema. The edematous fluid is 

 often blood-stained and the muscles are of a blackish or 

 blackish-brown color. The lymphatic glands are markedly 

 hyperemic. The internal viscera present but little altera- 

 tion visible to the naked eye. In the blood-stained serous 



