PROBLEM 128 



153 



Notice that the malarial parasite passes part of its life history in the body of the 

 mosquito, and part in the human body. The lower part of the figure repre- 

 sents a blood vessel in man. The parasites live part of their lives in the blood 

 corpuscles. Then they multiply and break out of the corpuscles. (See right 

 side of figure.) Using this figure and information from your Civic Biology, 

 work out the complete life history of the malarial parasite. 



What happens if these organisms are taken into the mosquito's 

 body? 



Note. — Only when both forms of cells are taken into the body of the mosquito 

 are the parasites able to continue their development there. 



Conclusion. — How might malaria be transmitted ? 



Problem 128 : To study the life history of the typhoid fly. 



Materials. — Raw meat, glass dishes. 



Method. — Expose pieces of raw beef where flies will Ught on 

 them. After a few hours cover in glass dishes or small battery- 

 jars with screen covers. 



Observations. — ■ Watch the meat. In pieces on which eggs were 

 laid by the flies describe the stages of development as they appear. 

 Do the larvae grow any? They are called maggots. How do the 



