THE INDIAN CORN 



157 



from one through the bean 

 stem. The most striking 

 difference is in the arrange- 

 ment of the vascular bundles. 

 Instead of being in a cylinder 

 (a ring in cross section), the 

 bundles are scattered through 

 the stem. Another impor- 

 tant point of difference is that 

 there is no cambium : a vascu- 

 lar bundle of the com con- 

 sists only of wood and bast. 

 There being no cambium, the 



Fig. 96. — Part of a cross section 

 through the stem of the Indian corn. 

 After Stevens. 



Fig. 97. — Lower portion of a 

 corn stem, showing the cluster of 

 roots growing from the base, the 

 brace roots, and one (the third) 

 secondary leaf. The very small 

 blade of the first secondary leaf 

 has withered, and only a portion 

 remains of the blade of the second 

 secondary leaf. 



stem cannot grow in thickness 

 after the cells of any partictilar 

 part are fully grown. This is 

 why the com stem is of about 

 the same diameter throughout 

 its length, instead of being 

 thicker toward the base as the 

 bean stem is. 



180. Foliage Leaves. — These 

 are alternately arranged, like 

 the leaves of the bean. A com 

 leaf (Fig. 95) has no leaf-stalk. 

 The lower part of the leaf forms 

 a sheath that surrounds the 

 stem for some distance above 

 the joint where the leaf is at- 

 tached. The upper, outspread 

 part of the leaf is the blade. 

 On the inner side of the leaf, at 

 the place where the blade joins 



