SUMMARY AND REVIEW. 



IV. — Mention the functions of the groups of 

 cells spoken of in this chapter. 



V. — Explain what you understand by the 

 term "disease" and give the cause of one serious 

 form of disease. 



VI. — Into how many classes may bacteria be 

 divided in order to simplify for study? 



VII. — Define bacteria, pathogenic bacteria, 

 saprophytic bacteria. 



VIII. — Prove that pathogenic bacteria are 

 foes to health. 



IX. — In what way do saprophytes benefit 

 mankind ? 



X. — Explain what would happen to plant 

 and vegetable and animal life if saprophytic 

 bacteria should be destroyed or become inac- 

 tive ? Give reasons for your answer ? 



