ANATOMY AND PHYSIOLOGY OF PLANTS. 249 



resembling the bud in the structure of its scales and the 

 developtment of its parts. 



6. The common apparent object of both radical and 

 caulinar bulbs, is the perpetuation of the plant. 



7. The buds of plants, whether producing leaves 

 only, flowers only, or both, consist of the necessary con- 

 stituents in an undeveloped state. 



They are usually composed, externally, of a number of concave 

 and overlapping scales, with others of a more delicate nature inter- 

 nally, and are connected with the stem or branch by means of a short 

 fleshy pedicle. 



8. Buds are not an essential part of the plant, but 

 when present, their indubitable office is to protect the 

 germ in its infant state. 



All plants are not furnished with them ; annuals have none, and 

 even trees and shrubs, to which they are proper, do not pro- 

 duce buds in hot climates ; because, perhaps, in those climates, 

 the tender germ requires no covering to protect it. In this, and all 

 cold countries, trees and shrubs are universally furnished with them, 

 and without the intervention of a bad, no new part is added to 

 the plant. 



THE LEAF-STALK OR PETIOLE. 



9. This part is nothing more than a prolongation of the 

 branch or stem, exhibiting upon dissection, an epider- 

 mis, a pulp or parenchyma, and bundles of longitudinal 



