42 
together they always sleep one more or less over the other. This 
from a single die. 
They sometimes kill and eat one another when kept in captivity. 
In one case seven young rats were being kept in a cage and o 
of the number was killed and eaten by the others. How far this 
trait holds good in the natural staie it is impossible to say, but, 
from quite young animals practising it, it is more than probable that 
sick or wounded ones are eaten by their companions. They do not, 
however, appear to be quarrelsome when caged together, though on 
one occasion a e adult female was found after a fight in one of the 
cages. They soon became reconciled to серыш and got quite tame, 
though they =н bite if given the chance. They are very nervous 
and timid and would ery out and stand up on their hind legs at the 
baek of the cage if frighten 
The brown-bellied rats appear to be much more fierce. One 
caught in a trap seriously hurt itself in frantie attempts to get 
through the wires. "The field rats have extremely sharp teeth and in 
many cases bit holes through the brass wire gauze of which the 
cages were made. 
FORMER ATTEMPTS TO DESTROY THE RATS. 
Many versus have been tried to lessen the numbers of the rats. 
en long on the under surface of a piece of it when held up 
horizontally, this likewise proved of no avail. The killing of them at 
e rate of over 800 per day has been already mentioned. 
PREVIOUS EXPERIMENTS WITH LOEFFLER’S TYPHI-MURIUM 
BACILLUS. 
I was informed by Dr. M. J. Wright, the State Surgeon, Perak, 
that the rat virus had been previously tried on the rats on an estate 
in Lower Perak, and he very kindly allowed me to see his office copy 
of the correspondence relating to the experiment. From this paper, 
R.-G.O. 5011/1900, it appears that in 1900 two tubes of the virus 
were received through the Director of the Institute for Medical : 
Research, Federated Malay States. They were unfortunately both 
broken in the post and arrived in Lower Perak in a dried and mouldy 
condition. The contents of the tubes were, however, put on bread an 
laced in the fields at Bagan Datoh Estate. Dr. J. T. Clarke, District 
n, Telok Anson, who conducted the experiments, writes that 
ults were negative, and it is quite резе, as he suggests, that 
as was dead at the time it arrived. 
