Prevention of Splenic Fever, Sfc, at the Brown Institution. 309 
Another guinea-pig, inoculated at the same time as the first, 
did not die till twelve hours later ; it presented similar ap- 
pearances, but there was more exudation at the points of 
inoculation. 
Some blood-stained serum from the heart of guinea-pig No. 1 
was kept in capillary tubes at normal temperatures for four 
weeks, and it was then used to inoculate two mice, with very 
minute quantities. One of these died in twelve hours, and was 
examined after nine hours. There was no local inflammation 
in the tail where it had been inoculated, and no inflammation 
of the peritoneum. The spleen was large and rather soft, the 
other viscera healthy, except slight injection of the pleura. 
Blood taken from the right ventricle was found to contain very 
numerous long rods, many of them measuring 80 /x in length, 
some containing spores. 
Another mouse was inoculated in the tail with a minute 
quantity of serum collected in the peritoneum of the previous 
one, and, like it, died in twelve hours. When examined, three 
and a-half hours after death, some inflammation was found 
extending along the surface of the abdomen, and some slightly 
turbid exudation in the peritoneum ; the latter containing a 
large number of long rods like those in the previous case. 
On comparing together specimens of blood from these ani- 
mals and some from cases of undoubted anthrax, a very close 
similarity is discovered. The chief differences are that the 
bacilli in most cases of true anthrax are much more abundant ; 
and that the bacilli in Cape fever were more slender. But I 
find a considerable difference in this respect in bacilli in 
anthrax ; in specimens from some animals they are decidedly 
smaller than in others. In other respects, their varying length, 
junction of two segments at an acute angle, or formation of 
long rods made up of nearly equal segments, they are very similar 
in appearance. 
In the viscera I did not find any important changes beyond 
those already mentioned in speaking of the lungs. 
It is indeed a most striking feature of all these forms of 
blood-poisoning that the changes in the organs are so slight in 
degree or may be quite undiscoverable. 
There is one other point of distinction from anthrax which I 
must note, viz., that the growth of the bacilli in cultivating 
fluids is much less voluminous than that usual with anthrax 
bacillus, although in its main features it is very similar. 
I was able to cultivate the organisms found in the blood, spleen, 
and peritoneal serum of the guinea-pig for several generations ; 
and also those from the peritoneum and pleura of the mice 
subsequently inoculated. The various stages were as follows : 
they were repeated again and again in successive cultivations, 
