24 LEAF-BUDS. 



The horizontal development is confined to 

 the cellular system of the bark, pith, and me- 

 dullary rays. 



The upwaj.'d and downward developments 

 are confined to the woody fibre and vascular 

 tissue. 



In this respect they resemble seeds; from 

 which, they differ physiologically in propagating 

 the individual, while seeds can only propagate 

 the species. 



When they disjoin from the stem that bears 

 them, they are called hdhs. 



In some plants, a bud, when separated from 

 its stem, will grow and form a new plant, if 

 placed in circumstances favorable to the pre- 

 servation of its vital powers. 



But this property seems confined to plants 

 having a firm, woody, perennial stem. 



Such buds, when detached from their parent 

 stem, send roots downwards and a stem up- 

 wards. 



But if the buds are not separated from the 

 plant to which they belong, the matter they 

 send downwards becomes wood and liber, and 

 the stems they send upwards become branches. 

 Hence it is said that wood and liber are formed 

 by the roots of leaf-buds. 



