DIRECTION OF GROWTH 



33 



seen outside the daughter-bulb. The Hyacinth-bulb (fig. 53) 

 has scales of both sorts ; there are true scale-leaves {fs), as well 

 as scales {fb) which are the persistent basal parts of green 

 leaves (/). In all these bulbs each new one {b) arises as an 

 axillary bud on the bulb of the previous year. The older bulb- 

 scales shrivel and give their contents to the younger parts. 

 The lower surface of the stem of the bulb gives off adventitious 

 roots. 



SUB-AERIAL STEMS— DIRECTION OF GROWTH. 



Occasionally the foliage-bearing part of a stem which is 

 above ground is so short that the leaves form a tuft, apparently 



Fig. 54. — Strawberry plant, showing runners. (From Dennert.) 



springing from the ground — e.g. Dandelion and Daisy. The 

 leaves are then said to be radical in position. 



Fig. 55. — Plant ol Convolvulus arvensis^ which is prostrate becaitse it has met with 

 no support up which it can climb. (After Dennert.) 



