310 Report on an Iiuiuinj in the Prevention of Splenic Fever. 
so that the various stages could be watched side by side in crops 
of different ages. 
The rods first formed were long and slender, measuring some- 
times (as in the mouse examined three hours after death) as 
much as 15 /u. to 90 yu, in length, and about '6 in thickness. 
They were usually quite motionless, but some of them moved 
very slowly along with a slightly wavy motion. 
These rods, when cultivated, grew rapidly to an enormous 
length, some extending almost the entire width of the field 
(about 200 jjb). In these longer ones there were sometimes, at 
an early period, indications of subdivision into shorter rods, 
from 10 to 30 /u. in length ; but they often produced the twisted 
rope-like forms before any subdivision. Once or twice a 
moving stage was observed in rods about 15 to 25 [x in length ; 
but this was uncommon. 
In these elongated rods the formation of spores proceeds in 
the usual manner, though, on account of their smaller size, the 
steps could not be so readily watched as in the ordinary anthrax 
bacilli. 
These spores were pretty regularly arranged in a definite 
order in the rods, sometimes in couples, i.e. the alternate spaces 
narrower. 
In the rods which had undergone partial division before the 
formation of spores, these were frequently more closely set 
together ; and the filaments broke down more rapidly into a 
mass of spores, some of which had escaped from the filament, 
others had been formed by its division. 
Although these observations are not sufficiently extensive to 
warrant any definite and final conclusions, they seem to me 
to indicate that the disease, although allied to anthrax, may yet 
be distinguished from it by the predominant affection of the 
lungs, by the relatively small number of bacilli which are found 
in the blood and organs, as well as by the size of the bacilli 
themselves. 
In true anthrax the growth of bacilli is enormous, their dis- 
tribution general throughout the body, and in many of the 
organs the blood -vessels are often found to be plugged by masses 
of them. 
In the Cape Horse-fever they are produced in relatively small 
numbers, and display a preference for certain sites, circulating 
in the blood and wandering out of the vessels at certain points, 
at which they appear to set up inflammatory changes, and lead 
to characteristic results which form the anatomy of the disease. 
In anthrax the blood is the site of their growth, and the sole 
anatomical characteristic in most cases is the swelling of the 
spleen, which is due to the peculiar relations to the blood. At 
the same time it must be allowed that cases of anthrax do occur 
