264 THE SEED PLANTS : FORMS AND LIFE HISTORIES 



can be clearly seen in longitudinal section of a bud 

 taken in the autumn. The food which supplies the 

 material for growth is stored, largely in the form of 

 starch, in the tissues of the corm. When the aerial 

 shoots are fully developed the base of each begins to 

 swell by the growth i^ thickness of the stem tissue, 

 and starch, made from the sugar produced by the 

 foliage leaves, is deposited in this tissue. Thus a new 

 corm is formed at the base of each aerial shoot, and 

 each new corm goes on growing so long as the foliage 

 leaves are ahve (May or June). During the summer 

 or autumn the new corms, covered by the scale leaves 

 which were developed at the base of the aerial stem, 

 and which gradually became dry and brown, become 

 detached from the old corm, which is now finished and 

 shrivelled, while the upper part of the aerial shoot, 

 also dead, is detached from the top of the corm. Mean- 

 while axillary buds develop in the axils of the scale 

 leaves of the new corms, swell and produce the rudi- 

 ments of next year's foliage leaves and flowers, so that 

 by October the new corms are " ripe." 



If the Crocuses are left in the ground, the new corms 

 develop where they are, and after a few years become 

 very crowded, so that the new corms are apt to be 

 small and feeble, often possessing only one new axillary 

 bud which is strong enough to flower. That is why 

 a better crop of flowers is produced if corms are taken 

 up as soon as the leaves die, and only the most vigorous 

 selected for replanting. 



Other examples of plants which go through the 

 winter in the form of corms are the Meadow Saffron 

 [Oolchicum autumnale) — ^found in meadows and woods 

 especially in the west of England — which produces its 

 new corm in the same way, but at the side of the old 



