q/'Dischidia Rafflesiana. 389 



petiole of ordinary form and a curiously modified limb, the lamina being an 

 appendage of the limb. I consider the inflected portion of the pitchers of 

 Dischidia as analogous to the moveable opercula of the more perfect examples 

 cited above, although in this it is continuous with the body of the pitcher. 

 Mr. Brown however says (foe. cit.), that the Ascidia of Dischidia have no 

 laminae. I may add, that petioles are much less liable to modifications than the 

 laminae. If the pitchers of Nepenthece, &c. are modified petioles, the cucullate 

 bractese of Marcgraviacece will be referable to the petiole of the bracteae. 



With respect to the Stomata, they exist on both surfaces of the leaves and 

 of the ascidia ; most abundantly on the concave surface of the leaf and the 

 corresponding inner surface of the pitcher: most of those developed on the 

 under surface of the leaf and outer surface of the pitcher are imperfect, the 

 degree of imperfection varying much. They are in particular remarkable for 

 the existence of an external cellular bourrelet, considerably elevated above the 

 surface and of a whitish colour (Tab. XVII. figs. 3 & 5). It is to their pre- 

 sence that the minute white dots existing on both surfaces of the leaves and 

 ascidia, and so particularly visible on the inner coloured surface of the latter, 

 are to be attributed. They appear to have a very slight connection with the 

 cuticle, being easily detached ; they are confined to their respective Stomata, 

 and have no communication of structure between one another ; and they appear 

 to be deciduous, since they are not met with in old ascidia. Each bourrelet 

 is composed of from 3 to 5 cells : their margins are somewhat inflected. Their 

 appearance is that of a cup-shaped gland. Are these originally parts of a cel- 

 lular epiderm, the remains of which are visible on many parts of the plant? 

 They cannot be referred to the peculiar epiderm, the discovery of which is due 

 to M. A. Brongniart, from their compound structure. 



The Stomata themselves are somewhat elevated above the cutis ; the sur- 

 rounding cells are parallelogram mic and disposed in circles, into the compo- 

 sition of which 3 or 4 cellules enter ; and each circle diminishes successively 

 in size from without inwards (Tab. XVII. figs. 4 & 6). The Stoma occupies 

 the space of the innermost circle, and in itself presents nothing unusual. In 

 many of those developed on the inner surface of the pitcher, the whole Stoma 

 is opake and has a grumous appearance. The cells surrounding those from 

 the inner side of the pitcher are colourless, while in those of the outer surface 



