ed mass of protoplasm, not
floating in the air at all, but transmitted only by the bite of a
mosquito. By a series of most interesting experiments, conducted by them
and by other scientists in other parts of the world, it has been
definitely proved that when a mosquito bites an individual suffering
from malaria, the mosquito draws up into his body, along with the blood
of the bitten person, some of the malarial parasites. In the body of the
mosquito, the parasite develops, requiring for a full-grown specimen
about seven days; then, if the mosquito bites another person, the
parasite is injected into the skin of the victim, and in the course of
about a week a good case of malaria ensues.

Fortunately, only a small proportion of the number of mosquitoes in the
world are capable of nourishing the malaria parasite. Under ordinary
conditions about 5 per cent of all mosquitoes found are malarial, and a
particular name has been given to those capable of transmitting the
disease. The ordinary mosquito is known as the "culex," while the
malarial kind is known as "anopheles." Figure 78 shows the
characteristic attitude of the two kinds by which the one can be
distinguished from the other when resting on a wall or ceiling. As will
be noticed in the drawing, the culex carries his body parallel to the
wall with his hind legs crossed over his back. The harmful mosquito, the
female anopheles, always hangs on by her front legs and has her body at
an angle of about forty-five degrees to the surface to which she clings,
her hind legs hanging down. The wings of the harmless mosquito are
usually mottled, while the wings of the malarial mosquito are of an even
color. The details of the behavior of the parasite on its long journey
from the original malarial patient through the body of the mosquito and
into the body of the person bitten is full of interest to the scientist,
who must, however, be provided with a good microscope to follow such
minute bodies; but the methods of avoiding the disease are more
pertinent to our present purpose.

While quinine is still recognized as the particular antidote for the
malarial poison, efficient as we know now because it is poisonous to the
parasite and not because it has any particular effect on the person, of
late years more and more stress is being laid on the elimination of the
mosquito. Naturally, if the mosquito can be destroyed and the
transmission of the disease thus prevented, there will be no fu