54 Malaria 



ity is not sufficiently rapid or universal to check their rapid 

 increase. 



The melanin granules set free during sporulation are also 

 taken up by the leukocytes and endothelial cells, the latter 

 becoming deeply pigmented at times. 



The spleen enlarges as the disease continues until it forms 

 the " ague-cake." The enlargement may cause the organ 

 to weigh 7 to 10 pounds. It appears to result from hyper- 

 trophy. The tissue is pigmented. The liver and kidneys 

 are also enlarged and pigmented. 



Prophylaxis. With the knowledge of the role of the 

 mosquito in the transmission of malaria, its prophylaxis be- 

 comes a matter of simplicity when certain measures can be 

 systematically carried out. There are two equally import- 

 ant factors to be considered the human being and the mos- 

 quito. The measures must be directed toward preventing 

 each from infecting the other. 



1 . The Human Beings. In districts where malarial fever 

 prevails, the first part of the campaign had perhaps best be 

 directed toward finding and treating all cases of malarial 

 fever, so that the parasites in their blood may be destroyed 

 and the infection of mosquitoes prevented. This is done by 

 the systematic and general use of quinin. 



All cases of malarial fever should be required to sleep in 

 mosquito-proof houses under nets, and as the mosquitoes are 

 nocturnal and begin to fly at dusk, the patients should shut 

 themselves in at that time. By thus killing the parasites in 

 the blood, and keeping the mosquitoes from the patients in 

 the meantime, much can be done. But where malarial 

 fever prevails, the mosquitoes are already largely infected, 

 hence the healthy population should also learn to respect the 

 habits of the insects and not expose themselves to their bites, 

 should screen their houses and their beds, and should take 

 small prophylactic doses of quinin to prevent the develop- 

 ment of the parasites when exposure cannot be prevented. 



2. The Mosquitoes. It is not known that the parasites 

 can pass from one generation of mosquitoes to another, 

 hence the mosquitoes to be feared are those that are already 

 infected. By making the houses mosquito-proof most of 

 the insects can be kept out, while those that get in can be 

 caught and killed. 



By draining the swamps and destroying all the breed- 

 ing places in and near human habitations, the number 



