COMMUNITY SANITATION 429 



which the insect draws when biting a diseased person. 

 These germs live in the body of the insect for some time, 

 multiplying rapidly. When they are ready to be injected 

 into new victims, they pass into the salivary glands of 

 the insect. From there they are injected into the blood 

 of the one bitten, where they multiply and produce the 

 disease. 



Malaria. This disease was formerly believed to be 

 due to damp night air or swamp air. We now know that 



FIG. 376. A Breeding Place for Mosquitoes. 



malaria is caused by the action of small parasites, protozoa, 

 which flourish in the body of the mosquito. The fact 

 that mosquitoes are more active at night and breed ex- 

 tensively in swamps accounts for the mistaken ideas 

 concerning malaria. 



If mosquitoes can be kept from biting people who have 

 malaria and then from biting other people, the malaria 

 question is solved. Since mosquitoes breed in stagnant 

 water and damp places, all puddles, ditches, and swamps 

 should be drained, or treated with kerosene (Figure 376). 

 The kerosene treatment is very effective where other 

 means are not practical. The adult mosquito lays its 



