INTRODUCTION. 11 



The tuber of the latter is more elongated, rising 

 out of the ground and increasing itself by side- 

 shoots crowned with leaves, which, being slipped 

 off, become new plants. 



^-. The bundled or pendulous tuber is that of 

 the Dahlia^ &c. The lateral tubers are vivi- 

 parous progeny, and are produced at the same 

 time the principal is developed, each having one 

 or more buds on or near the apex. 



"" Fibrous roots, or those having neither bulb 

 nor tuber, are well exemplified in the pink and 

 carnation. From the under-side and edges of 

 the crown, thread-like fibres descend and spread 

 themselves around ; they are also divided and 

 subdivided, in their progress, into very many 

 slender filaments. The crown of such kinds of 

 plants is a flattened conical body, composed of 

 many smaller ones, the bases of partly advanced 

 or incipient shoots, each surrounded by several 

 pairs of radical leaves, which mostly remain sta- 

 tionary on the body of the parent plant. The 

 younger leaves are seated on, and rise in pairs 

 with the flower-stems; these last being elongated 



