ROOT AND STEM. 143 



each internode grows will depend upon the 

 habit of the plant and upon incidental cir- 

 cumstances. Some plants habitually pro- 

 duce longer internodes than others. Inci- 

 dental circumstances appear to be more 

 closely associated with the length of the in- 

 ternode, however. An apple-tree which is 

 neglected may produce internodes one or 

 two inches long, while another tree which 

 receives good culture may grow them two 

 feet long. The leaf-bud which is formed in 

 the fall contains the rudiments of a comjolete 

 branch which is to grow the next summer ; 

 there are just as many nodes or joints in 

 that minute bud-branch as there will be in 

 the future twig, but the length to which the 

 twig will grow between these joints will be 

 determined by the character of the season 

 and the thrift of the plant. The root has 

 no nodes or joints ; it goes on in its peculiar 

 searching manner, branching and rebranch- 

 ing with little or no regularity. 



There is another still more apparent dif- 

 ference between the root and the stem : the 

 root descends into earth and darkness, but 

 the stem rises into air and sunlight. But 

 why should there be this opposite habit in 

 parts so closely associated ? There is noth- 



