INTRODUCTION. 15 



stance, that they are increased in magnitude 

 during that period. It is true, that the places of 

 the first developed buds are the first to decay ; 

 but then the new buds become more numerous 

 and dispersed over the enlarged body of the tuber 



Fugitive or annual tubers are such as the 

 orchis. They are perennial by succession, not 

 by duration, like the anemone. A single tuber, 

 before its developement, contains two distinct 

 principles; the first is expanded in the air, to 

 produce seed ; the second is formed into a new 

 tuber in the earth, to be perfected into leaves 

 and stem, &c. the following year. When the 

 first has ripened its seed, the whole dies ; leaving 

 its successor completely formed, to undergo the 

 like changes in due time ; so that, in fact, it is 

 only a modification of perpetual reproduction to 

 continue existence. 



But all tubers, whether permanent or fugitive, 

 are furnished with active fibres, which mainly, 

 if not entirely, assist in furnishing the necessary 

 supphes for expansion of the plant, whether in 

 the air or in the earth. 



