276 Report on an Inquinj into the Nature, Causes, and 
system, and as some of these investigations afford practical sug- 
gestions, I propose to refer to them briefly in the present Report. 
Inoculation of Bovine Animals with the Poison of Anthrax trans- 
mitted through Guinea-pigs. 
It is now a generally recognised fact that the contagium or 
virus of splenic apoplexy (anthrax) is a low vegetable organism, 
the so-called Bacillus anthracis. This organism is found in 
enormous quantities in the blood and certain of the tissues of 
animals dying of the disease. It has been shown by repeated 
experiment that it may be artificially cultivated outside the 
living body, under conditions suitable to its growth and pro- 
pagation ; that it nevertheless retains its virulent property, which 
may be transmitted from generation to generation, so that a far 
distant progeny of the bacillus first grown from the blood of the 
living animal, if introduced into the system of another living 
animal, gives rise to all the phenomena of the disease. 
Moreover, the disease is readily communicable to a large 
number of known animals, rodents being especially susceptible, 
guinea-pigs and mice being amongst the most easily inoculated. 
In transmitting the disease through rodents to bovine animals, 
two distinct methods may be employed ; the one of direct in- 
oculation, the other of inoculation with the cultivated virus. 
The direct method, that employed by Mr. Duguid in his 
experiments, consists in inoculating the bovine animal with the 
blood or spleen of a guinea-pig which has died of the disease 
produced either by inoculating from a cow, or from one of a 
series of which the first was inoculated from a cow. That is, if 
guinea-pig A is inoculated from a cow, B from A, C from B, 
D from C, and then a cow direct from D, it would be an ex- 
ample of direct inoculation. Or it might be inoculated direct 
from A or B or C. Dried blood, if properly secured, retains in 
parts its infective power for a considerable time, so that this 
process of transmission may have been carried over some 
months. 
The " cultivation " or indirect method proceeds on the basis 
of the fact already indicated, that the poison (the Bacillus 
anthracis^ may be artificially grown in a cultivating fluid in 
successive generations, and that the last generation may then 
be inoculated and produce the symptoms and fatal result of the 
disease. 
Seeing that the object of my experiments was to inoculate 
bovine animals with a virus modified by its transmission 
through the guinea-pig, it may appear that it would be de- 
