250 NA T URE-STUD Y RE VIEW 



In what parts of the plant do each of the following store food? 

 (Test for Starch. See Experiment 1.) 



Bulbs. — Note in a vertical section of a bulb that has sprouted 

 and has had for some time, and still has, good, healthy green 

 leaves, what these leaves connect with in the bulb {stem at bottom 

 of bulb) and how the parts of the leaves within the bulb compare 

 with the parts above in color, thickness, closeness. Why? 



Were the other layers or scales of the bulb once the lower 

 parts of leaves? 



Compare with the cabbage. In what does it store food ? (Thick- 

 ened leaves). 



Show a vertical section and have children observe the thickened 

 stem to which the leaves in the center of the head are attached. 

 Is there food stored there also? 



Com.pare a crocus or gladiolus or cyclamen bulb (corm) and note 

 that food is stored in a broad, thick stem. 



Compare a potato. — Food stored in the thickened stem (tuber). 

 Why not a root? Has buds ("eyes") from which new branches 

 (sprouts) come. Show some long sprouts. 



Compare a sweet potato. — A root (has no "eyes"). 



Compare a beet or carrot. — Mostly roots, but may have buds at 

 top. 



What comes from those after the roots have been standing in a 

 jar of water? — Leaves, etc. 



If planted again, from such roots, will come flower stalks, and 

 blossoms, producing seeds, a work which they could not complete 

 the first year. 



(Hence, another use for stored food?) 



Such plants are called biennials. 



Is the cabbage a biennial? 



How and when are its seeds obtained? 



Compare the thickened, underground parts of bloodroot, 

 violet, etc. — ^Underground stems (rootstocks) . 



Compare the large winter buds of lilac, poplar, etc. (Note 

 what comes from them when allowed to stand in water), with a 

 cabbage-head and with a narcissus bulb (vertical sections of each). 



The latter are also practically large buds, What do buds 

 contain? How did they prepare for the "burst of spring?" 



Name any trees that bloom before they leef out? 



Do maple trees bloom early? What is their stored food made 



