MALIGNANT (EDEMA 113 



living animals or unopened carcases), and bacilli are detected exhibiting 

 capsules when stained by Johne's method (see Technique, 22), 

 then the diagnosis is assured. 



When an animal has been dead for several days, bacilli develop in 

 the cadaver somewhat difficult to differentiate from the Bacillus 

 anthracis. In such cases gelatine plate cultures must be instituted, and 

 mice and guinea-pigs inoculated. In the inoculation of animals, the 

 presence of the bacillus of malignant oedema must be guarded against, 

 as it is often present, the inoculated animal dying of malignant oedema 

 in spite of the presence of the Bacillus anthracis. This error can be 

 prevented if the animals are ' inoculated cutaneously ' with the suspected 

 material, when only the Bacillus anthracis develops, and a false diagnosis 

 is avoided. When putrefaction is too far advanced in a carcase under 

 examination, the anthrax bacilli are sometimes completely annihilated 

 by the concurrence of other species, so that a diagnosis is no longer 

 possible. 



MALIGNANT (EDEMA. 



(Ger. Bacillus (Edematis Maligni. Fr. Vibrion Septique.) 



This organism is very widely distributed in nature ; it is found in 

 manured garden earth, in filth and dust, in house drains, and also in 

 the intestines of animals. 



Microscopical Appearances. The bacilli are somewhat narrower 

 than the Bacillus anthracis, and about the same length, but differ in the 

 ends of the rods being rounded, and not squarely cut across. The 

 peculiar bamboo rod shape found in anthrax bacilli is also absent. 



Motility. Motile, possessing 3 to 12 flagella, which are attached at 

 the ends as well as the sides of the rods (see Photomicrograph, Plate I., 

 Fig. 5) ; the motility is somewhat weak. For special methods of staining 

 flagella, see Technique, 23, 24. 



Staining Reactions. The bacilli obtained from the animal body, 

 and from young cultures, stain easily with the ordinary aniline dyes. 



By the Gram method positive results are only obtained when the 

 specimen is stained for twenty-four hours at 37, or with equal parts of 

 anilin water, alcohol, and 5 per cent, carbolic acid solution of gentian 

 violet for fifteen minutes. With the Cladius method the bacilli are 

 easily stained in a few minutes. 



Spore Formation. The spores are formed generally in the middle 

 of the rods, and are sometimes broader than the bacillus, forming a 

 spindle or clostridium. 



Biological Characters. The bacillus is strongly anaerobic, grow- 



H 



