NATURE'S WOODCRAFT: A CHAPTER ON STEMS 



213 



unlike buds, with thick, fleshy scales folded round a conical axis (fig. 273). 

 Corms are somewhat similar, but their scales are thin, few, and mem- 

 branous; and the axis of a corm is much thicker than the axis of a 

 bulb (fig.. 272). The Crocus, Cyclamen, and Gladiolus offer good examples 

 of the corm ; and instances of bulbs are furnished by the Lily, Onion, Star 

 of Bethlehem, Snakes- 

 head, and Hyacinth. 

 Both these forms of 

 underground stem are 

 storehouses of food 

 material, husbanding 

 the strength and energy 

 acquired by the plant 

 during one season for 

 the exigencies of the 

 next. The reserve of 

 food is largely drawn 

 upon by the plant at 

 the time of flowering, 

 but if flowering be pre- 

 vented, a very consider- 

 able saving of expendi- 

 ture is the result : while 

 the bulb, which is con- 

 tinually receiving fresh 

 supplies of nutriment 

 from the leaves, is found 

 to be larger at the end 

 of the growing season 

 than at the commence- 

 ment. A Lily, or other 

 bulbous plant, by having 

 the buds cut out year 

 after year just before the 

 period of flowering, ac- 

 cumulates an abnormal 

 quantity of food- 

 material (starch) ; and 

 when at last the plant 



is permitted to flower, it is able to compensate itself for former deprive- 

 ments by making an exceptionally grand display. Herein lies the secret 

 of the size and beauty of many " florists' flowers." 



Many of these bulbous plants grow in places where, for many months, 

 owing to the absence of rain, the land is a desert. Deep in the ground 



Photo by] 



IE. Step. 



FIG. 267. PILLWOBT (Pilularia globulifera). 



Scarcely to be distinguished from grass at a glance. It has a long, thread- 

 like, creeping rhizome from which long, slender leaves arise singly or in pairs, 

 and between their bases are the spherical spore-cases. EUROPE, NOttTH OP 



THE ALPS. 



