448 BACILLUS OF MALIGNANT (EDEMA 



tion of antitoxic serum to the treatment of the human disease ' 

 will be looked forward to with interest. 



Bacillus fallax. — This organism was separated by Weinberg and 

 Seguin, and the name was given by them on account of its resembling the 

 b. welchii. It is smaller than the latter organism, being both somewhat 

 thinner and shorter. It is Gram-positive, and in cultures forms spores 

 which are usually subterminal in position. It possesses lateral flagella ' 

 and is feehly motile. The growths resemble those of b. welchii, but the 

 young surface colonies are more transparent and the older ones have a 

 more irregular margin. The action on milk is much less marked, the 

 formation of clot and gas usually occurring only after several days ; the 

 action on sugars also is feebler and more restricted. It has no digestive 

 effect on- casein or on coagulated serum. It thus may be described as 

 a non-proteolytic bacillus with somewhat weak saccharolytic action. 

 Recent cultures produce a gelatinous cedema on injection into a guinea- 

 pig ; they, however, soon lose their virulence. > 



Vibrion Septique (Pasteuk), Bacillus of Malignant 

 CEdema (Koch). 



This organism was first discovered by Pasteur in putrefy- 

 ing carcases. He described its characters, distinguishing it from 

 the anthrax bacillus, which it somewhat resembles morpho- 

 logically, and also the lesions produced by it. He found that 

 it grew only in anaerobic conditions, but was able to cultivate 

 it merely in an impure state. A similar organism was later 

 more fully studied by Koch, which he considered to be the same 

 as Pasteur's vibrion septique. He pointed out, however, that the 

 disease produced by it is not really a septicaemia, as immediately 

 after death the blood may be free from the bacilli. Accordingly 

 he gave to it the' name bacillus of malignant cedema, from its 

 pathogenic effects in animals. There has, however, been a con- 

 siderable amount of confusion as to the essential features of 

 these organisms, the original descriptions being naturally 

 incomplete, and some observers have described under the term 

 bacillus of malignant oedema certain non-pathogenic anaerobes 

 which produce merely putrefactive changes. 



In pre-war times " malignant cedema " in the human subject 

 was usually described as a spreading inflammatory oedema 

 attended with emphysema, and ultimately followed by a certain 

 amount of gangrene. In only some cases of this nature, how- 

 ever, the bacillus of malignant cedema is present, and it is 

 usually associated with other organisms which aid its spread. 

 One of us, however, observed a fatal case in which the bacillus 

 was present in pure condition. Here there oecurred intense 

 cedema with swelling and induration of the tissues, and the 



