14 



OEGANOGEAPHY AND GLOSSOLOGY. 



A bulb is coated [h. tunicatus) when the outer leaves overlap each other so 

 as completely to sheathe the base of the stem {Narcissus, fig. 39 ; Onion, fig. 40) it 

 is scaly [h. squamosus) when the leaves are narrow, almost flat, and imbricated m many 



Lily. Scaly bulb, cut vertically. 



39. Narcissus. Go.ated bulb, 

 I, disk ; t, stem ; /, leciyes. 



41. Colchicum. Solid bulb. 



rows {Lily, fig- 38) ; solid {h. solidus) when the leaf-bases are very close and confluent 

 with the disk, so that the latter appears to form the entire stock {Colchicum, fig. 41). 

 In the Croctis (fig. 42), the underground 



stock is formed of two or three solid bulbs, 



superimposed like the beads of a chaplet. 



The primitive bulb (1), which terminates in 



a flower, pushes out a lateral shoot, which 



perpetuates the plant. After flowering, it 



swells considerably, to nourish the shoot 



which is to succeed it ; this latter flowers 



in its turn the following year, and emits a 



shoot like its predecessor; to nourish this it 

 40, Onion. Coated bulb, g^^gjjg ^^^ ^^^^^ .^^^^^^ ^2) above the original 



one, which then gradually decays. At the flowering of the third shoot (3) adven- 

 titious roots grow from the base of the second bulb, which soon withers and dries 

 like the first. At the side of the middle bulb a lateral bulbil often springs, which 

 separates from the parent, and becomes a fresh plant. 



In comparing rootstocks with bulbs, it is easy to perceive that they differ 

 only by the greater or less length of the disk, and the more or less fleshy texture 

 of their underground leaves. The rootstock may thus be regarded as a bulb with 

 a horizontally lengthened disk, and the bulb as a short rootstock with fleshy leaves. 



42. Crocus. 



Superimposed bulbs. 



