crumbs in die two dishes, (b) Explain.- («.} What is the purpose of_ drying hay or fruit be- 

 fore putting it away for future use? 



15. SUMMARY, (a) How do moulds, yeasts, and bacteria differ from one another in 

 size and movement, (b) When yeasts act upon starch and sugars what is one of the prod- 

 ucts given off? (c) From the results of your experiments with bacteria and moulds what may 

 be inferred concerning their presence in soil; in air; on plants; on insects and larger animals? 

 (d) What conditions as regards temperature and moisture seem most favorable for the devel- 

 opment of these minute plants? (e) What are two principal methods of preserving foods? 

 (f) Can you give any reason why foods such as corn and wheat keep better than potatoes, 

 apples, peaches, strawberries, etc. (g) Are bacteria ever animals? 



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