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BACTERIOLOGY. 
infected blood the malarial parasites are taken into the 
stomach and undergo reproduction. After seven to 
ten days they find their way to the salivary glands. 
When the mosquito bites man the parasites are ex¬ 
creted with the saliva into the wound. In the blood 
the parasites enter and develop within the red blood- 
cells. As they grow they fill more and more of the 
corpuscle and finally become segmented into smaller 
bodies that are to become parasites. When this de¬ 
velopment is complete, requiring forty-eight or seventy- 
two hours, depending upon the type of parasite, the 
red blood-corpuscle is ruptured and the segments and 
a toxin are set free in the circulating blood, causing the 
chill and fever that are so characteristic of the disease. 
In this way more and more blood-cells are attacked 
and destroyed, which explains the anemia. 
The diagnosis is made by finding the parasites 
in the blood. They can be found by examining either 
fresh preparations or stained specimens. In the for¬ 
mer the parasites can be seen inside the red blood- 
corpuscles as colorless bodies containing granules of 
pigment that are in active motion. In the stained 
specimens the parasites are motionless, but are much 
more distinctly seen. 
The spread of malaria is controlled by all meas¬ 
ures that aim at the extermination of the mosquito. 
As the mosquito lives and breeds in swamps and ponds, 
attention should be directed to these places first. The 
larvae from which the mosquito develops live and grow 
near the surface of stagnant water. If oil is spread 
