so A GUIDE FOR THE STUDY OF ANIMALS 



7. What is encysting ? Name some protozoa which en- 

 cyst. How long may an encysted animal live ? When do 

 they encyst ? Why ? 



8. Give methods of reproduction among protozoa. Which 

 method is fitted for rapid multiplication ; for withstanding 

 drouth ; for renewing vitality .■' 



9. Many scientists speak of protozoa as immortal. What 

 argument is there to support such a statement .' 



10. Why are no protozoa large animals ? Give at least 

 two reasons. 



11. Why are protozoa so numerous.'' Why more nu- 

 merous in stagnant water .'' 



12. Where are protozoa found .' 



13. Why are protozoa so widely distributed.' 



14. Write the probable history of a piece of chalk. 



1 5-. What connection is there between protozoa and some 

 polishing powders ? 



16. Where in the human body are malarial protozoa 

 found .'' How are they transferred from one human being 

 to another ? Why is there likely to be more malaria in 

 newly settled regions than in older ones ? If you were 

 obliged to spend some time in a region where malaria ex- 

 isted, what precautions would you take .' 



17. Name other diseases caused by protozoa. How are 

 they fought ? 



18. What beneficial effect have some protozoa upon the 

 water of stagnant ponds and ditches ? How may some 

 forms injure water for household purposes ? 



19. Give at least three reasons for thinking that protozoa 

 are the most ancient animals. 



20. Why are protozoa of great importance to the 

 world .' 



