SUMMARY 291 



Summary. — In this chapter we have found that a part of the Kfe 

 history of the malarial parasite is spent in the red blood corpuscles 

 of man and that its sexual stages are passed in the body of the 

 anopheles mosquito, thus making it necessary for the parasite to 

 have two hosts in order to complete its life history. Yellow fever is 

 caused by a parasite which is transferred to man by the mosquito 

 aedes. 



The house fly is found to be a disease carrier, also the flea, body 

 louse, and probably the bedbug. 



The parasitic worms that are most serious enemies of man are 

 the tapeworm, trichina, and hookworm. The last named is one 

 of the largest economic problems in the tropics. 



Problem Questions 



1. In what ways do animals affect man ? 



2. Show how malaria is transmitted. How is it caused ? What conditions 

 must exist in order that it be transmitted ? 



3. What are three ways to exterminate mosquitoes from a locality? 



4. Is it possible to do awaj^ with malaria ? May the same be said of yellow 

 fever ? 



5. How is yellow fever spread ? How can the diseass be fought successfully ? 



6. What other diseases are insect-carried? 



7. What different kinds of organisms cause disease? 



8. How would you fight the fly pest in your home ? In your town ? 



9. What are the best means of exterminating the rat? (Look up Lantz's 

 report, Farmers' Bulletin 396.) 



10. Describe the method of hookworm infection and the method of cure. 

 How can we rid the world of hookworm disease ? 



Problem and Project References 



Hunter, Laboratory Problems in Civic Biology. American Book Company. 

 Broadhurst, Home and Community Hygiene. J. B. Lippincott Company. 

 Folsom, Entomology. P. Blakiston's Son and Company. 

 Hunter and Whitman, Civic Science in the Community. American Book 



Company. 

 Marshall, Microbiology. P. Blakiston's Son and Company. 

 Reese, Economic Zoology. P. Blakiston's Son and Company. 

 Winslow, Healthy Living. Charles E. Merrill Company. 

 Farmers' Bulletins 33, 369, 444, 569, 670, 734, 896, 1057, 1354, 1408. 

 Public Health Reports. Supplement 29, 569. 

 United States Dept. of Agriculture. Bulletins 132, 260. 

 United States Bureau of Fisheries. Economic Circular 17. 



