wall or ceiling, hangs away at an angle of about
forty-five degrees from it.

The Culex lays her eggs in sinks, tanks, cisterns, and water about
houses, but the Anopheles deposits her ova in shallow pools and
sluggish streams, especially those on which is a growth of green scum
or algae. Such are the main distinguishing features of the
malaria-carrying mosquito, the Anopheles, and the commoner house
variety, the Culex.

To prevent malaria, mosquito bites must be prevented by nettings in
houses, especially for the protection of sleepers. Pools, ponds, and
marshy districts must be drained in order to destroy the breeding
places of Anopheles, and in the malarial season, petroleum (kerosene)
must be poured on the surface of such waters to arrest the development
of the immature insects (larvae).

The mosquito is believed to be the sole cause of yellow fever, being
capable of communicating the germ of the disease to man by its bite
two weeks after it has itself been contaminated with the germ in
feeding on the blood of a yellow-fever patient. This invaluable
discovery was made by Dr. Walter Reed, U. S. A., in 1901, as a result
of his labors and those of other members of the yellow-fever
commission of the U. S. Army in Cuba, involving the death of one of
the members of the commission (Dr. Lazear), and utilizing the heroism
of a number of our young soldiers who voluntarily offered themselves
to be bitten by mosquitoes that had previously bitten yellow-fever
patients, and who experimentally occupied premises containing all
sorts of articles infected by yellow-fever patients. The result of
their research proves that yellow fever is not contagious at all, in
the usual sense, but is communicated only through the medium of
mosquitoes. This shows the fallacy of many quarantine rules regarding
yellow-fever patients, and of the fear of nursing the sick, and will
result in controlling the disease.

In the case of malaria or yellow fever, there is a vicious circle into
which man and the mosquito enter; malaria and yellow-fever patients
contaminate the mosquitoes which bite them, and the mosquitoes in
their turn infect man with these diseases. A patient with malaria
coming into a nonmalarial place, and being bitten by mosquitoes, may
lead to an epidemic of the disorder which becomes endemic. To
terminate this condition, it is necessary to prevent the contact of
man with mosquitoes and to kill these insects. Both malaria and
yellow