TUBERS AND BULBS 



35 



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. 

 Future growth is, therefore, pro- 

 vided for by the storage. Bulbous 

 plants are characteristic of many 

 dry countries. 



54. 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 flowers 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 purchased 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. Place a potato tuber in a tumbler or cup in a window so that 

 the bottom of the tuber will be in the water. 



