Zbc Stores of tbe Stem 29 



cactus stems are green and leafless ; the thick rind 

 acts the part of leaves in preparing food. They 

 shoot up into tall, strong columns, expand into 

 melon-shaped masses, or into that succession of 

 fleshy, rudely-oval discs with which we are familiar 

 in the " pear cactus ;" also there are other fantastic 

 forms. The stem bears the sessile, usually showy 

 blossoms, and is abundantly furnished with sharp 

 prickles, to prevent the plant's destruction by thirsty 

 animals. 



" What do stems bear ?" Let us ask this question 

 and answer it as we ramble. " Leaves, flowers, roots," 

 we speak briskly ; " fruit," more slowly. " Nothing 

 else?" "No." They bear much more than these. 

 Excrescences of the rind sharpen into prickles, as in 

 the blackberry and rose, protecting the plant from 

 devastation. The honey-locust, hawthorn, thorn- 

 apple, and plum have large spines which are stunted, 

 hardened branches, or stem tips. The barberry has 

 thorns formed of undeveloped leaves, hardened 

 almost like steel. We know that these are altered 

 leaves, as they grow each in an axil, under a bud. 

 These are all protective appendages to preserve the 

 plant for seed bearing. 



Stems also produce tendrils for climbing purposes. 

 Some tendrils grow out straight, until they reach 

 a place of support ; there they adhere by means of a 



