CHARACTERS OF THE BACILLUS. 395 



the skin and subjacent parts. In many cases of this nature 

 the bacillus of malignant oedema is present, associated with 

 other organisms which aid its spread, whilst in others it 

 may be absent. One of us has, however, recently observed 

 a case in which the bacillus was present in pure condition. 

 Here there occurred intense oedema with swelling and in- 

 duration of the tissues, and the formation of vesicles on the 

 skin. Those changes were attended with a reddish dis- 

 coloration, afterwards becoming livid. Emphysema was not 

 recognisable until the limb was incised, when it was 

 detected though in small degree. Further, the tissues 

 had a peculiar heavy but not putrid odour. The bacillus, 

 which was obtained in pure culture, was present in enor- 

 mous numbers in the affected tissues, attended by cellular 

 necrosis, serous exudation, and at places much leucocytic 

 emigration. The picture, in short, corresponded with that 

 seen on inoculating a guinea-pig with a pure culture. The 

 term " malignant oedema " should be limited in its applica- 

 tion to cases in which the bacillus in question is present. 

 In most of these there is a mixed infection ; in some this 

 bacillus may be present alone. 



This bacillus has a very widespread distribution in 

 nature, being present in garden soil, dung, and various 

 putrefying animal fluids ; and it is by contamination of 

 lacerated wounds by such substances that the disease is 

 usually set up in the human subject. Malignant oedema 

 can be readily produced by inoculating susceptible animals, 

 such as guinea-pigs, with garden soil. The bacillus is also 

 often present in the intestine of man and animals, and has 

 been described as being present in some gangrenous 

 conditions originating in connection with the intestine in 

 the human subject. 



Microscopical Characters. The bacillus of malignant 

 oedema is a comparatively large organism, being slightly 

 less than i ^ in thickness, that is, thinner than the anthrax 

 bacillus. It occurs in the form of single rods 3 /A to 10 /x 

 in length, but both in the tissues and in cultures in fluids 

 it frequently grows out into long filaments, which may be 



