60 MONOCOTYLEDONS^. 



jected a successor tuber, becomes extinct. Thus these 

 plants are perennial by a succession of tubers pro- 

 duced from each other, and not by duration, as is the 

 case with Anemone, or Cyclamen. A spontaneous 

 motion is attributed to the petals of some species of 

 this order, which is a phenomenon not yet satisfac- 

 torily explained. 



Fig. 26. 



a, the old tuber, which perishes with the leaves and flower ; 6, 

 the new tuber. 



Five other orders stand at the head of the 

 class Monocotyledonece. Among- the genera those 

 of Zdmia and Cycas, are, from the form and 

 texture of their appendages, the most remark- 

 able. They have the appearance of dwarf palms; 

 their foliage is of a rigid membranaceous character, 

 and very durable. Their short, thick stems, are com- 

 posed of the bases of fallen leaves in the same man- 



