160 



CHANNELS AND CAVITIES FOR FLUID. 



rating themselves from the parent ; but, when they have once 

 formed their own leaves and root-fibres, they are but little con- 

 nected with it, and may be detached without injury. 



241. The usual form of leaves is often remarkably changed ; 

 and many of the varieties produced in different plants, seem to 

 have for their object, to collect water from the atmosphere and 

 convey it to the roots. The large expanded leaves of the Arum 

 tribe, for example, have a deep channel down the midrib ; and 

 this is continued along the petiole, so that the water collected by 

 the leaf is conveyed to the point of the stem from which it springs. 

 In the common Teazel (Dipsacus) of our own fields, and the 

 Tillandsia, or Wild Pine of South America, there are hollows 

 capable of holding a considerable amount of water, at the point 

 of union of the leaf- stalk with the stem. 



242. But the most remarkable contrivances of this kind, are 

 those known as pitchers. The plants furnished with these cu- 

 rious receptacles are termed Pitcher-plants ; and several kinds 

 of them are known. In the Sarracenia, which is a native 



of Canada, these 

 pitchers may be 

 distinctly seen to 

 be formed, by the 

 very deep chan- 

 neling of leaves 

 and leafless stalks, 

 the edges of which 

 fold towards and 

 meet one another, 

 so as to form a 

 complete vase ; 

 the mouth being 

 guarded by a sort 

 of hood, formed 

 by the top of the 

 leaf. In the Ne- 

 penthes, orChinese 

 Pitcher-plant, the pitcher is of more complex and singular con- 



FIG. 69 DIFFERENT KINDS OF PITCHERS, 



<i, pitcher of Sarracenia ; b, pitcher of Nepenthes ; c, 

 pitcher of Cephalotus. 



