662 CONSERVATIVE ORGANS. [LECT. XI. 



separated from the water, and absorbed through 

 the substance of the sac, or is a secretion of the 

 plant. All the species of Utricularia, which are 

 not uncommon in our ponds and ditches, have 

 these bladders attached to the roots ; but in Al- 

 drovanda vesiculosa, an inhabitant of the Italian 

 marshes, they are present as foliar appendages. 



d. The hook (hamus) is generally described 

 among the bristles, and in point of structure, in 

 the majority of instances, it certainly belongs to 

 these bodies ; but I prefer placing it here, as it is 

 in every sense of the word a real fulcrum. It is 

 well illustrated in Cleavers, Galium Aparine, the 

 angles of the stalk and the margin and midrib of 

 the leaves of which are furnished with hooks, 

 which enable the plant to climb to the tops of the 

 hedges near which it is generally found. The 

 most beautiful specimen, however, of the ve- 

 getable hook is found on the pitcher of Nepenthes 

 (see p. 672), in which it serves the purpose of sup- 

 porting that curious appendage, when it is over- 

 loaded with fluid. 



vi. Foliaceous appendages. These, as their 

 name implies, resemble leaves in several particu- 

 lars ; and this similitude extends even to their 

 anatomical structure. There are three kinds of 

 foliaceous appendages ; the stipule, the bracte or 

 floral leaf, and the pitcher. 



a. The stipule (stipula) is a foliaceous organ, 



