394 



MALIGNANT CEDEMA. 



in short, corresponded with that seen on inoculating a guinea- 

 pig with a pure culture. The term " malignant oedema " 

 should be limited in its application to cases in which the bacil- 

 lus 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 sus- 

 ceptible 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. 



Bacillus oedematis maligni. — Microscopical Cliaracters. — 

 The bacillus of malignant oedema is a comparatively large or- 

 ganism, being 

 slightly less 

 than I /u. in 

 thickness, that 

 is, thinner than 

 the anthrax ba- 

 cillus. It oc- 

 curs in the form 

 of single rods 

 3 yu. to lo /u, in 

 length, butboth 

 in the tissues 

 and in cultures 

 in fluids it fre- 

 quently grows 

 out into long fil- 

 aments, which 

 maybe uniform 

 throughout or 

 segmented at 

 irregular inter- 

 vals. In cultures on solid media it chiefly occurs in the form of 

 shorter rods with somewhat rounded ends. The rods are motile. 



«^: 



'%. 



# 

 t 



• 



■M 



%■ 



\ 



Fig. 132. — Film preparation from the affected tissues in a case 

 of ma,lignant oedema in the human subject, showing the spore-bear- 

 ing bacilli. Gentian-violet, x 1000. 



