46 THE GEELONG NATURALIST. 
once began to gnaw the body of the dead vole, and they, within 
a few days, died of the disease. The same result had previously 
been observed in the case of the mice. After a great number 
of experiments, conducted with the utmost care, the professor 
satisfied himself that this bacillus would cause the disease in 
field voles, when supplied to them with their food; and, on the 
other hand, that the bacillus was harmless as regards birds, 
cats, fowls, pigeons, pigs, rabbits, sheep, &c. Hence, he hoped 
that the new bacillus typhi murium would afford a weapon 
which could be effectually used against the field vole pest. 
These conclusions were reached at the end of 1890. 
In March, 1892, a plague of field voles infested the plains of 
Thessaly, north of Greece. After many ineffectual attempts 
were made to put down the pest, the Greek Government was 
. ultimately induced to ask Professor Leofler to try the result of 
this bacillus on a large practical scale. 
Arrangements were made, and the professor and an assistant 
went to Greece, taking with them some cultivations of the 
bacillus. At first experiments were made on the particular 
species of vole found there, and they were found to be even 
more susceptible to the disease than those previously experi- 
mented on. The bacillus was cultivated in large tin vessels, 
and taken to the infected district. The landowners interested 
in the experiment caused their dependents to render assistance. 
Soldiers were sent to summon the peasants from the neighbour- 
iug villages, and tell them to bring slices of bread with thém. 
Each one brought, in a wicker basket, a sufficient quantity of 
bread with him for the land on which he worked. The bread 
was emptied into the tin vessels, and thoroughly soaked with 
the fluid. As might be supposed, the peasants were half afraid 
of the fluid, thinking it was poison; but their doubts were 
dispelled when they saw fowls, pigeons, dogs, horses, sheep, 
goats, &c., fed with the bread; indeed, some of the staff ate 
pieces of the bread themselves, and thus proved that the bacillus 
' was harmless to man. The bread was taken from the vessels 
and, in small pieces, dropped in vole burrows, strewn near crops, 
and placed wherever it was thought the voles would find it. In 
addition to this, numbers of voles were caught and inNpculated 
with the pure culture of the bacillus, and then let loose to carry 
the disease to their comrades. In this way the bacilli were 
abundantly disseminated amongst the voles. The result was 
wonderful: within a few days the districts which before had 
simply swarmed with the pest seemed deserted. Dead and 
dying voles lay about in all directions, and were soon devoured 
by the buzzards and other birds. In every case when a dead 
vole was examined it was found to have died from the disease 
caused by the bacillus—a disease allied to typhus in the human 
subject. 
