79 



CHAPTER XII. 



OF THE KOOT, AND ITS DirTERENT KIXDS. 



\Ve begin the dcBcription of the completely formed 

 vegetable by its root, being the basis of all the rest, as 

 well as the iirst part produced from the seed. Its 

 use in general is two-fold ; to fix the plant to a com- 

 modious situation, and to derive nourishment for its 

 support. This part is therefore commonly plunged 

 deeply into the ground, having, as u-e have already 

 shown, a natural tendency to grow downwards. In 

 some cases however, when plants grow on the stems 

 or branches of others, as the Dodder or Ciisciita, se- 

 veral Ferns, and a portion of the Orchis tribe, tiie root 

 is closely attached to the bark, from which it draws 

 nourishment, by the under side only, the upper being 

 bare. 



The Root consists of two parts, Caiuk.v tlie body 

 of the root, and Radkula the fibre. The latter only is 

 essential, being the part which imbibes nourishment. 



Roots are either of annual, biennial or perennial 

 duration. The first belong to plants which live only 

 one year, or rather one summer, as Barley; the se- 

 cond to such as are produced one season, and, living 

 through the ensuing winter, produce flowers and fruit 

 the following summer, as Wheat; and the tliird to 



