THE AUSTRALIAN NATURALIST. 43 
Ss 
alone without counting the thousands in the Congo Free 
State and other localities. Sleeping Sickness is now known 
to extend over a million square miles in Central Africa. 
According to authorities like Koch and Manson, arsenic 
in the form of atoxyl is as efficacious in the early stages of 
sleeping sickness, as quinine is in malaria. Removal of the 
natives from the low-lying marsh land, and the destruction 
of the cover among which the flies shelter are the methods 
adopted. 
The next, and perhaps, one of the most serious pests to 
man, is the common House Fly (Musca domestica) and thou- 
sands of deaths are caused every year through the presence of 
this fly in our streets and houses. This fly lays her eggs in 
fresh horse droppings and decaying vegetable matter. On 
such material the maggots feed, develop and pupate and 
bring forth a fresh crop of flies. The house fly lives on filth 
and then covered with filth-germs of all kinds flies into the 
house, settles upon our food and tumbles into the milk. It 
is one of the most active agents in the spread of typhoid 
fever, tuberculosis, Asiatic cholera, dysentry and other in- 
testinal diseases. 
This has been so strongly demonstrated in the United 
States that Dr. Howard proposes to drop the harmless sound- 
ing name of “‘house fly’’ and called it the “Typhoid fly.” 
Under proper sanitary conditions there should be no filth 
or stable manure allowed to accumulate in the streets or 
back-yards of any town; if all matter in which flies can lay 
their eggs is destroyed or covered over and removed there 
will be no fly pest. Another group of insects closely related 
to the flies are the fleas, though very unlike them in general 
appearance. House fleas are the best known, they deposit 
their eggs in dusty places where the slender white larvae 
live and finally pupate in tubular silken cocoons. Next comes 
the common dog flea, many birds as well as wild animals, 
among them our marsupials, have their own peculiar flea. 
Shipley (Journal of Economic Biology, 1908), gives a lot of 
fifteen distinct species of fleas that have been obtained from 
the fur of the two common cosmopolitan rats, the House Rat 
(Mus rattus) and the Black Rat (Mus decumanus) and it 
is with the fleas infesting these little animals that the en- 
tomologist and biologist has had to deal in studying the trans- 
mission of disease germs to man. 
During the outbreaks of 
one of the common rat fl 
transmitting the germs of 
man. And in Australia 
Sydney, thus when the dise 
plague in India it was proved that 
eas (Pulex cheopis) was capable ot 
plague from plague-stricken rats to 
the bubonic plague was spread in 
ased rats are swarming’in the sewers 
