542 



Our Surroundings 



Eggs 



Water Level 



Larva 

 WaterLevel J 



Dept. of Agriculture. 



THE METAMORPHOSIS OF A 

 MALARIA MOSQUITO 



air, and the presence of oil on 

 off their air supply and soon kills 



have lived in these glands a 

 few days these parasites may 

 pass along with the saliva into 

 the blood of the person bit- 

 ten. Here they soon establish 

 themselves in the red blood 

 corpuscles where they grow 

 larger and develop spores. 

 The growth of these spores 

 causes serious injury to the 

 corpuscles, breaking them 

 down and releasing the spores 

 into the blood current together 

 with a poisonous substance 

 which has been generated. 

 This poisonous substance af- 

 fects the human system so 

 seriously that chills and fever 

 follow. Physicians prescribe 

 quinine in large doses to cure 

 malaria. No other effective 

 remedy has been discovered. 



The only sure way to elim- 

 inate malaria in sections where 

 it exists is to exterminate the 

 mosquitoes. This may be done 

 by draining pools of stagnant 

 water or by pouring oil on 

 their surfaces. Mosquitoes lay 

 their eggs on water, and these 

 soon hatch into active larvae, 

 or "wigglers", which shortly 

 develop into less active pupae. 

 Though both larvae and pupae 

 live in the water, they breathe 



the surface of the water shuts 



them. 



