of 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 (loc. cit.), that the Ascidia of Dischidia have no 
laminz. I may add, that petioles are much less liable to modifications than the 
lamine. If the pitchers of Nepentheæ, &c. are modified petioles, the cucullate 
bracteze of Marcgraviacew will be referable to the petiole of the bracteze. 
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 arid of a whitish colour (Tas. 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 parallelogrammic 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 (Tas. 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 
