426 A MANUAL OF BACTERIOLOGY 



hours. Post mortem, the subcutaneous tissues around 

 the seat of inoculation will be found to be cedematous and 

 blood-stained, with more or less development of gas. The 

 internal organs are only slightly altered, but the spleen 

 may be somewhat enlarged. The juice from the seat of 

 inoculation will be found to contain a mixture of organisms, 

 but in the blood and organs few will be found. Under the 

 capsule of the spleen, however, long slender rods may 

 be seen ; these are the bacilli of malignant oedema. 



Morphology. The bacillus of malignant oedema is a long 

 and slender rod, several of which may be united into a 

 thread. It is motile, possesses several flagella, and is 

 readily stained by the ordinary anilin dyes, but not by 

 Gram's method. It spores freely at temperatures above 

 20 C., the spores being large and central. 



Cultural characters.- The bacillus of malignant cedema 

 is strictly anaerobic. In a deep stab in glucose-agar it 

 forms a thick line of growth in the needle track, with 

 irregular outline and greyish-white in colour. There is 

 profuse development of gas, accompanied by a foul odour, 

 and attended with disruption of the medium into several 

 portions. 



The bacillus of malignant oedema is an organism which has to 

 be distinguished from anthrax, and there should be no difficulty in 

 doing this. Post mortem, the spleen is rarely found much enlarged 

 in malignant oedema, the organism is not very abundant, is almost 

 entirely absent from the blood, and is only found under the capsule 

 of the spleen, not at its centre. If, however, several hours have 

 elapsed since death occurred, the organism may have wandered 

 into the blood and the centre of the spleen. The bacillus of 

 malignant oedema is motile under anaerobic conditions, the anthrax 

 bacillus non-motile ; the former occurs as a long slender filament, 

 which on staining is seen to consist of two or three long segments ; 

 it does not stain by Gram's method (except by Claudius's modifica- 

 tion), and is strictly anaerobic. 



