Pitchered Insectivorous Plants . 
25 7 
follows the line of development taken by the seedling leaves, 
in that the concave area separates into a basal midrib portion, 
whose bounding ridges grow out to form a pair of laminar 
lobes, and an upper midrib portion whose bounding ridges 
become the wings of the pitcher, while deepening of the 
dimpled depression behind these lobes gives rise to the pitcher 
cavity. 
But the extreme leaf-apex projects from the first beyond 
the depression as a rounded mass. This, as development pro- 
ceeds, gives rise either to one ventral median swelling which 
grows forward and downward over the cavity, or — as figured 
by Hooker in N. phyllamphora — two swellings may appear, 
one on each side of the middle line. By continued growth of 
the former, or by fusion and growth of the latter, the lid is 
formed. 
The terminal part of the leaf apex may further give off from 
its side paired filamentous lobes, or a single dorsal lobe in the 
middle line, though a rather irregular disposition also occurs. 
They are by no means conspicuous, but I regard them as of 
special morphological interest. 
When the lid and filiform apex are fully grown, one 
finds that, just as in the seedling, the vascular bundles of the 
pitchered midrib which have converged give off two strong 
diverging bundles into the former, then pursuing their course 
upward they give off very delicate branches into the lateral 
or median lobes, and finally merge into cellular tissue of the 
extreme tip. It should also be noted that the adult lid in 
some species shows a slight tendency to division or indentation 
at its free extremity. 
How then are we to explain the lid and filiform apex with 
its delicate lateral or median lobes. First, I think, it may be 
conceded that the converged bundles at the top of the pitcher 
truly represent the midrib of the leaf reformed or recom- 
pacted after being inflated to receive a dorsal involution of 
itself— the pitcher. 
One almost hesitates to give it so peculiar an explanation, 
but I can scarcely see that the lid is to be regarded otherwise 
