THE ANGIOSPERMAE : STEMS ^43 



to the bulb. In the Tuhp this food promotes the development of one or 

 more axillary buds into new daughter bulbs, which absorb the surplus of food 

 from the old bulb and consequently replace it. In Narcissus the food is stored 

 in the leaf bases, both of the current year and those persisting from the two 

 or three previous years. An axillary bud also develops into a new flowering 



Fig. 933. — Dentaria bulhifeia. 

 axillary bulbils. 



Shoot with 



bud and one or more other axillary buds may develop into daughter bulbs 

 which, however, do not replace the mother bulb, which remains active for years. 



The bulb of the Bluebell {Scilla non-scripta) is intermediate in character 

 between the two examples given above. The scales consist of the bases of 

 the foliage leaves of one year only but its growth is sympodial. 



Among the Orchids we commonly find green bulbous structures at the 

 base of the leaves, which are called pseudo-bulbs. These are really tuberous 

 stem or branch segments, sometimes involving the whole length of the stem, 



