162 



THE BOOK OF NATURE STUDY 



four or five inches below the level of the soil, might at first sight 

 be mistaken for a bulb. It is really, as is best seen on splitting 

 it lengthways in half (Figs. 78, 79), a flat cake-like stem, bearing 

 the remains of a number of thin brown scale-leaves. The food 

 material is here stored in the stem, not in the thickened scale- 

 leaves as in a bulb. The swollen underground stem is called a 



corm. The summit of the corm bears 

 one or several buds, which stand in the 

 axils of leaves borne upon it. Each of 

 these buds grows into a flowering shoot, 

 the growth taking place in the autumn 

 and being completed in the spring, when 

 the leaves and flower appear above 

 ground. 



The plant is fastened in the soil by 

 numerous unbranched roots, which 

 spring from the base of the corm, 

 and serve to obtain the water and 

 food salts required for growth. The 

 material for the growth of the shoot 

 and flower is obtained from that stored 

 up in the corm, which has served its 

 use as soon as the flowering is over 

 and decays later in the year. A new 

 corm is formed by the enlargement 

 of the base of the flowering shoot, 

 and this gets stored with the material 

 manufactured by the foliage-leaves, and 

 remains to carry on the growth of the plant next season. 



When more than one shoot is present as many new corms 

 will form (Fig. 78), and then on the decay of the old corm will 

 become isolated from one another. In this way the plant is 

 multiplied vegetatively, and does not merely persist year after 

 year. 



The shoot of the Crocus consists of a short stem bearing a 

 number of closely crowded, thin, scale-leaves which enclose the 

 parts within. These scales persist on the base of the stem when 

 it enlarges to form the new corm. Above them come three to 



FlG. 78. Yellow Garden Crocus. 

 Corm, with the flowering 

 shoots beginning to grow, 

 cut in half. (After Baillon.) 



