USE OF THE STOKED FOOD 



35 



or both of two purposes : they may be storehouses for 

 food; they may be means of propagating the plant. 

 The storage of food carries the plant over a dry or cold 

 season. By making bulbs or tubers, the plant persists 

 until spring. A lunch is put up 

 for a future day. Most bulbous 

 plants are natives of dry countries. 



50. Three corms growing on 

 an old one. Gladiolus. 



REVIEW. What do you understand 

 by food reservoirs? How is the presence 

 of starch determined? Where may starch 

 be found ? Of what service to the plant 

 is this stored food ? How are the flow- 

 ers and leaves enabled to start so early 

 in spring ? Define tuber. Root tuber. 

 Stem tuber. Crown tuber. Give examples. Define bulb. Scaly 

 bulb. Tunicated bulb. Bulblet. Bulbel. Give examples. Define 

 corm. Cormel. What two purposes do congested parts serve ? 



NOTE. The pupil should examine various kinds of bulbs and 

 tubers. If these are not at hand, many kinds can be bought of 

 seedsmen or florists. Secure onion, narcissus, hyacinth, gladiolus, 

 crocus, potato. Cut them in two. Study the make-up. Test them 

 for starch. Plant some of them in pots or boxes. Observe how they 

 grow. In the onion and some other plants most of the stored food 

 is sugar. 



Potato tuber set in a glass of water and kept in a window. 



