62 



MORPHOLOGY OF STEMS. 



botanic.-il descriptions. In fact, while they differ from naked 

 corms in having some investment, the}* differ from true bulbs 

 only in the greater size of the solid axis and the fewness of 

 /\ ^ the investing scales ; 



the stem or solid bod}* 

 mnking the greater part 

 of the corm, but a very 

 small part of a proper 

 bulb. There are, more- 

 over, all gradations be- 

 tween the two. 



A Bulb, as compared with a corm, may be said to be -an 

 exceedingly abbreviated stem, reduced to a flat plate, from the 

 lower face of which roots are produced, from the upper face, 

 leaves in the form of scales ; these scales being either reduced 

 and thickened leaves or the thickened bases of ordinary leaves. 

 Compared with buds (73), it is a very flesh}- bud, usually large 

 and subterranean, the axis of which never elongates. It is a 



120. 



provision for future growth, the stored nourishment of which Is 

 deposited in the leaves, or the homologues of leaves, instead of 

 in the stem. 



FIG. 111. Corm of Crocus, the few thin envelopim; scales removed, showing their 

 sears, \\hich mark the nodes, the shrivelled vestige of the last year's conn at the base, 

 and lm. Is developing into new ones on various parts of its surface. iu. Vertical section 

 of a similar corm, \\iili a terminal and one lateral luid. 



l''l ( ! 1 !::. Section of a tnnieuted bulb of the Onion. 



FKi. II I Vertical section of the bulb of the Tulip, showing its stem or terminal 

 budlc) and t \\o axillary buds (/. ft). 



FIG. 11"). Bull i of a Garlic, with a erop of young bulbs. 



KM;, in; Vertical section of the corm of a Crocus: </. new buds. 



FIG. 117. Vertical section of the corm of ( 'olehicum (/<). with the withered corm of 

 the preceding (<i), and the forming one (c) for the ensuing year. 



