1 9 4 ELEMENTARY ZOOLOGY. 



great. The parasites produce all ^orts of disturbances, from mert, 

 inconvenience and functional derangement, such as anemia and 

 fevers, to the complete destruction of organs. 



In protecting himself from most of these parasites, man has a 

 complete means of escape by the perfect cooking of the meats which 

 he uses. Rare beef and uncooked pork are the chief means of 

 infection. 



212. Topics for Themes in Zoology or English. i. 



Consider the economic importance to man of the para- 

 sites included in this chapter. 



2. Make a table of all the worm parasites you can find 

 description of, giving the following facts: the name; the 

 host in the mature or sexual stage; the position in the 

 body and the results on this host; the host in the non- 

 sexual stage; its position and the results to the host. 



3. Give an account of the hook-worm of the Southern 

 States. How do human beings become infected by it? 

 What part of the body does it attack? What are the 

 symptoms of the disease? 



4. Give an account of the methods whereby man may 

 protect himself from each of the principal parasites 

 mentioned in this chapter. 



5. Illustrate from this group the degeneration of organs 

 that comes from the parasitic habit of life. 



6. In what ways do the intestinal parasites in this 

 group adhere to the wall of the digestive tract? 



7. Prepare for the class, and draw on the board, a 

 diagram of the reproductive organs of the tape- worm, 

 indicating the function of each portion of it. 



8. What arguments could you advance for considering 

 the tape- worm a segmented individual? For considering 

 it a colony of individuals? Similarly for the animal 

 figured in Fig. 9? 



