AND ITS DIFFERENT KINDS. 81 



The fibres of the root, particularly those extremities 

 of them which imbibe nourishment from the earth, are 

 in every case strictly annual. During the winter, or 

 torpid season of the year, the powers of roots lie dor- 

 mant, which season therefore is proper for their trans- 

 plantation. After they have begun to throw out new- 

 fibres, it is more or less dangerous, or even fatal, to re- 

 move them. Very young annual plants, as they form 

 new fibres with great facility, survive transplantation 

 tolerably well, provided they receive abundant supplies 

 of water by the leaves till the root has recovered itself. 



Botanists distinguish several different kinds of roots, 

 which are necessary to be known, not only forbotani- 

 cal purposes, but as being of great importance in agri- 

 culture and gardenino;. The generality of roots may 

 be arranged under the foUowinn; heads. 



1. RadirJihrGsa.fg. 5. A Fibrous Root. The most 

 simple in its nature of all, consisting only of fibres, 

 either branched or undivided, which convey nou- 

 rishment directly to the basis of the stem or leaves. 

 Many grasses, as Poa annaa^ Engl. Bot. t. 1 141, 

 and the greater part of annual herbs, have this kind 

 of root. The radical fibres of grasses that grow in 

 loose sand are remarkably downy, possibly for the 

 purpose of fixing them more securely to so slippery 

 a support, or to multiply the surface or points of 

 absorption in so meagre a source of nutriment. The 

 fibres of some parasitical plants already alluded to, 



G 



