A study in the Morphology of the Leaf. 245 
following conclusion : — That the leaf of Nepenthes is not a 
simple but a branched one ; regarding the spur at the back of 
the lid as the organic apex of the leaf, the lid which arises on 
its frontal or adaxial face, more or less distinctly below its 
extreme lip, and with a two-lobed form, may be regarded as 
representing two coalescent pinnae. The whole leaf would then 
consist of (1) a phyllopodium, winged throughout its length, 
terminating in the spur, and developing the pitcher itself as an 
involution of its upper surface ; (2) a pair of pinnae, which 
show congenital coalescence across the frontal face of the 
phyllopodium, and constitute the lid of the pitcher. 
I see only one other way of interpreting the facts. It might 
be possible to regard the lid as being truly the apex of the 
leaf, while the spur might be recognised as an outgrowth of 
the abaxial or lower surface of the leaf close to its apex, as in 
the leaf of Iris 1 ; but against this view is to be set the 
difficulty of explaining the two-lobed character of the lid 
while young, its venation, and its emargination when mature 
without any trace of a central spine at its apex. Moreover, 
observation of stages of development, such as those shown in 
Figs. 5-7 and 10-13, though they do not show the point so 
definitely as might be wished, indicate, I think, plainly enough 
that the organic apex of the leaf is represented by the spur, 
while the lid arises on its adaxial surface, though very little 
below its apex. I therefore think that the latter interpretation 
of the facts is untenable. 
Adopting then the view that the leaf is a peculiarly de- 
veloped phyllopodium, bearing two pinnae which show con- 
genital coalescence, it remains to draw comparisons with other 
leaves. I am not aware that any case exists of such coales- 
cence of pinnae across the frontal or adaxial face of the 
phyllopodium. It is obvious that Griffith’s comparison with 
the leaf of Bauhinia does not exactly fit. There the terminal 
spine, or true apex of the leaf, lies between the two pinnae, 
which are sessile upon the phyllopodium, being inserted upon 
Compare Goebel, Bot. Zeit. 1881, p. 96. 
