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GENERAL SCIENCE 



QUESTIONS 



1. What is the meaning of the word " germ "? 



2. Why should you be careful about putting your fingers in your 

 mouth or nose? 



3. How do germs cause disease in the body? 



4. What would happen if the white corpuscles of the blood were 

 removed? 



5. Why does a doctor know that a person will get well if a fever 

 " turns " ? 



6. Why is it wrong to say that people inherit disease? 



7. Why does a drinking man have less chance of getting well 

 from a severe illness? 



DISEASES CAUSED BY PROTOZOA 



Malaria. Malaria is caused by protozoa that live in the little 

 red corpuscles of the blood. They are injected into the body by 



a kind of mosquito called the 

 anopheles. The diagram will 

 show how very different it is 

 from the culex or common mos- 

 quito. Malarial mosquitoes do 

 not travel very far from the 

 place where they live. The 

 wind often blows the ordinary 

 mosquito great distances, but 

 the anopheles mosquito has 

 the habit of clinging to bushes, 

 shrubs and weeds near the place 

 where it hatches. 



The mosquito inserts its 

 proboscis through the skin of a 



FIG. 190. The malarial mosquito. 



Courtesy of Am. Mus. Nat. Hist. 



human being, and sucks out the 

 blood. In order to remove the blood from a person, the mosquito 

 must dissolve the little red corpuscles, since they are too large to 

 pass through the opening in its proboscis. Hence the mosquito 



