On the Disappearance of the Anthrax Bacillus after Death. 267 
putrefactive germs is the so-called malignant oedema bacillus, 
which, as regards size and shape, is so like the anthrax bacillus 
that the one may readily be mistaken for the other. The 
malignant oedema bacillus belongs to the class of anaerobic 
organisms — that is to say, it will not grow or multiply in the 
presence of free oxygen — and hence the deoxygenated blood of 
the dead animal is a most excellent medium for its propagation. 
As soon as the breath is out of an animal that succumbs to 
anthrax the invasion of the blood and organs by putrefactive 
germs begins, and, pari passu , the anthrax bacilli disappear. 
The invasion always starts from the bowel, and it proceeds with 
great rapidity in the chest and belly, as these parts cool slowly 
after death, and warmth is favourable to the growth of bacteria. 
When an anthrax carcass is left unopened, the invasion by 
putrefactive bacteria is sometimes so complete within twenty- 
four hours that not a single anthrax bacillus can be detected 
by microscopic examination in any of the organs in the chest or 
abdomen ; but in the blood of the ears or the feet the anthrax 
bacilli may be recognisable on the third day after death. These 
statements are based on observations that have been made in 
the Research Laboratory during the last three months, and they 
indicate that when an animal is unexpectedly found dead, and 
anthrax is suspected, if the carcass is already partially putrid 
blood from an ear or a foot ought to be examined in preference 
to spleen-pulp or blood from one of the large veins of the body. 
At the present time the material sent to the Laboratory for 
examination in suspected cases of anthrax is almost always the 
spleen or a part of it, and in a considerable proportion of cases 
a positive opinion cannot be given because of putrefactive 
changes. 
When the post-mortem can be made within an hour or two after 
death the naked-eve appearance of the spleen is by itself gener- 
ally sufficient to enable one to decide whether the case is one of 
anthrax or not, and if any doubt remains a microscopic examina- 
tion will remove it. But if, as is generally the case in anthrax 
of sheep, the animal is not found until some hours after death, 
and if putrefactive changes have already made considerable pro- 
gress, it would probably be a wise plan to abstain from a com- 
plete post-mortem examination, and to simply cut off an ear in 
order that the blood in its veins may be submitted to microscopic 
examination. Such a proceeding obviates the soil contamination 
inseparable from an ordinary post-mortem examination, and it is 
attended with no risk to the operator. Besides, as already said, 
although simple it is much more likely than the ordinary post- 
mortem to lead to a correct diagnosis. 
