INVERTEBRATES; PROTOZOA 219 



undergoing several changes, until the animal germs are 

 ready to be injected into their victim, when they pass 

 into the salivar}^ glands of the mosquito. In biting, the 

 mosquito always injects a little saliva into the wound and 

 with this go the germs. These enter the blood, multiply 

 rapidly and cause the disease. 



If mosquitoes can be kept from biting people who have 



A "MALARIAL" SWAMP. 

 A breeding place for mosquitoes. 



these diseases or if infected mosquitoes can be kept from 

 biting other people, such diseases will not spread. The 

 best way to keep mosquitoes from biting is to exterminate 

 them. Since mosquitoes breed in stagnant water, all old 

 dishes or small pools where water accumulates should be 

 emptied and drained. Larger stagnant pools should be 

 drained or have a film of kerosene spread over their surface 

 by frequently pouring a little of the oil on the water. 



