ENTOMOLOGICAL NEWS. 357 
ters and the district plague sub-stations live fleas have been 
fom numerous rats (as many as ninety-seyen from a 
le rat) which had been dead from periods ranging from 
to sixty hours. 
The British Indian Plague Commission has demonstrated 
md a doubt the method of rat flea plague transmission. 
reds of plague rat fleas have been carefully dissected and 
ternal organs minutely inspeeted for any evidence of 
xe bacilli. The salivary glands, the theoretical centre of 
were, after many painstaking attempts, successfully 
i from the body cavity. These were examined and a 
re like organism was found within the secretory ducts. In 
va yn, many fleas were crushed and inoculated into healthy 
54 . These latter, in every instance where the fleas had been 
ie: fon. yed from plague rats, succumbed to typical plague lesions. 
Itw gy for granted upon experimental evidence that the 
is, n mission was due directly to the co-operation of the salivary 
gland: fe ‘the action of the blood-sucking mandibles and 
Lee ats 
GS 
G roa t 
wi 
i ge . 
Ina cond series of experiments the commission attempted 
t further the validity of this theory. Live fleas were re- 
d from septicemic Plague Rats and placed in small 
als covered with flea net gauze. A flea-clean healthy animal 
’ selected and from a small area on the back the hair was 
cs ey The mouth of the vial was then placed against the 
' smooth skin and the flea permitted to bite through the gauze, 
Bz er biting, the insect was immediately withdrawn and the 
animal placed in a flea-proof cage and observed. A similar 
ry a was taken and treated in an identical manner, but im- 
bai si on withdrawing the flea, after it had bitten, a plati- 
auth needle loopful of a plague flea’s intestinal evacuation was 
_ tubbed into the bite. These experiments were duplicated and 
_ the results showed a marked uniformity. In no instance did 
4 the flea bite alone prove fatal, but in a large percentage the 
bites which were accompanied by the inoculation of the intes- 
tinal discharges caused a rapid death with post mortem plague 
positive verifications. It appears, then, that the disease trans- 
a 
; a 
an 
a 
“7 
