46 



MORPHOLOGY OF STEMS AND BRANCHES. [LESSON 6. 



Some 



of the bulb are the bases of leaves may be seen at once by follow- 

 ing any of the ground-leaves (root-leaves as they are incorrectly 



call./" ^own to their 

 origin in the bulb. 

 Fig. 75 represents 

 one of them from 

 the White Lily ; the 

 thickened base, which 

 makes a scale, being 

 cut off below, to show 

 its thickness. After 

 having lasted its time 

 and served its purpose as foliage, the green leaf dies, down to the 

 thickened base, which remains as a scale of the bulb. And year 

 after year, as the bulb grows from the centre, to produce the vege- 

 tation and the flowers of the season, the outer scales yield up their 

 store of nourishment for the purpose, and perish. 



110. Each scale, being a leaf, may have a bud in its axil, 

 of these buds grow into leafy and flowering stems 

 above ground : others grow into new bulbs, feeding 



on the parent, and at length destroying it, in the same 

 way that corms do, as just described (10G). 



111. When the scales are broad and enwrap all 

 that is within so as to form a succession of coats, one 

 over another, the bulb is said to be tunicated or coated. 

 The Tulip, Hyacinth, Leek, and Onion afford such 

 familiar examples of coated bulbs that no figure is 

 needed. When the scales are narrow and separate, 

 as in the Lily (Fig. 73), the bulb is said to be scaly. 



112. BulbletS are small bulbs formed above ground 

 on some plants ; as in the axils of the leaves of the 

 common bulbiferous Lily of the gardens, and often in 

 the flower-clusters of the Leek and Onion. They are 

 plainly nothing but bulbs with thickened scales. They 

 never grow into branches, but detach themselves when 75 



full grown, and fall to the ground, to take root there and form 

 jiew plants. 



113. From the few illustrations already given, attentive students 



FIG. 73. Hull) of the Moadow or Canada Lily. 74. The same, rut through lenpthwise. 

 FIG. 75. A lower leaf of White Lily, with its base wnder ground thickened into a bulb- 

 cale. 



