CHAP. XI STORAGE 59 



4. In what sorts of countries or in what sorts of places do 



Cacti grow? 



5. How does this explain the much thickened stem and lack 



of leaves? 



6. Of what use are the spines to the Cactus ? 



II. Take a plant of the Agave or Century Plant and 

 notice : 



1. The short stem. 



2. The stout thickened leaves. 



3. Make a sketch of this plant. 



4. How often does the Century Plant blossom? 



5. What happens to the plant after blossoming? 



6. Find out whatever you can about the Pulque, manufac- 



tured by the Mexicans from the juice of the Agave. 



7. In what sorts of countries are Agaves found? 



8. Loosen the epidermis of one of the leaves with a knife 



and peel off a piece. Notice its thickness and firm- 

 ness. What is the reason for this? 



9. How does the Agave protect itself against grazing ani- 



mals? Why should this be necessary? '/ 

 &// <U*~^- ^ \iw*<s4i*~~f - I 



III. Examine a plant of Iris which has been removed 

 carefully from the soil in which it was growing. Notice : 



1. The thickened, horizontal, underground portion and 



2. The transverse scars. What caused them ? 



3. Is this thickened portion, root, stem, or leaf? 



4. Write down your answer and give your reasons for it. 



5. Make a sketch of the Iris. 



IV. Take a Potato and examine it, noticing : 



1. Its general size, shape, and color. 



2. Does the Potato grow above or below ground? 



