THE LEAVES. 85 



saddle flower, with its leafy cups half filled with water and 

 dead insects, which abounds in the bogs of the Northern and 

 Middle States. This pitcher may be conceived to be formed 

 by the cohesion of the edges of a partly formed phyllodium. 

 If we imagine a dilated petiole with its partially formed lamina 

 to curve over and unite at its edges, a leaf like that of the 

 Sarracenia will evidently be formed, in which the pitcher will 

 be simply a hollow petiole, whilst the hood at its summit is 

 produced by its abortive lamina or blade. 



In Utricularia, or bladderwort, the leaves form sacs called 

 ampulla, which are filled with air, and float the plant in the 

 water at the time of flowering. 



But the most remarkable case of leaf cohesion, is seen in the 

 Nepenthes distillatoria, or pitcher plant of the East Indies. In 

 this instance, the petiole when it first leaves the side of the stem, 

 is round, or of its usual shape, then it expands into a leaf-like organ 

 or phyllodium, and next it is contracted into a tendril, finally it 

 forms into a phyllodium, the sides of which cohere together so as to 

 form a pitcher, which is surmounted at the summit by the 

 abortive lamina or blade, in the shape of a lid. This pitcher 

 is constantly filled with about half a pint of pure water, which 

 is not collected from without, as in the Sarracenia, but is 

 secreted by the plant : for the lid surmounting their summit 

 constantly and accurately closes the orifice of these pitchers, 

 and their internal surface is of a glandular structure. In 

 Ceylon, where this plant is common, it is called by the natives 

 by a word the signification of which is monkey cup ; because 

 these cunning animals when thirsty, and there is no stream at 

 hand, open the 'lid and drink the contents. Men also travelling 

 or hunting in the woods, often find the water contained in these 

 vegetable pitchers a means of assuaging their thirst. 



8* 



