Pitcher ed Insectivorous Plants . 263 
Additional reasons can be advanced in favour of this. Thus 
in S.JIava, the strong median bundle after being joined above 
the level of the middle of the lid by the lateral bundles 
runs up, and before reaching the extreme top of the lid 
passes off as a filiform process. The extremity of this pro- 
cess in large leaves exhibits a peltate or cuplike cavity abun- 
dantly studded with honey glands (Fig. 10). We have here, 
therefore, an undoubted approach to terminal fusion of leaflets 
such as gives rise to the lid of Nepenthes . Again, in those 
leaves of S,flava and S, Drummondii which do not pitcher, 
the midrib always ends in a simple curved spur (Fig. 8), 
just beyond the depression which has been arrested in its 
attempt at pitcher formation. Were the lid merely an ex- 
pansion of the midrib and not composed of leaflets we should 
at times expect to see the rudiment of it formed at the sides 
of the curved spur. This I have never observed. But the 
most interesting conditions to my mind are those presented 
by 5. variolaris and S. psittacina. In the former the upper 
part of the pitchered midrib arches over the orifice and thus 
becomes convex, a little higher a constriction from side to 
side occurs, beyond this the lobes of the lid enlarge and 
become strongly convex, while their upper parts form two 
rounded projections on each side of the midrib, so that the 
lid resembles a convex emarginate leaf. 
In S. psittacina the leaves all lie parallel to the ground with 
their dorsal flap uppermost. The top of the pitcher over- 
arches very strongly and then contracting bounds a small 
orifice, so that the leaf in appearance exactly resembles that 
of Darlingtonia without its bilobed lip. On more careful 
examination one finds that the vascular tissue of the pitchered 
midrib becomes compacted and terminates in a slightly curved 
point considerably above (natural position), i.e. further removed 
ventrally from, the orifice than the actual margin, and that 
a dorsal laminar outgrowth from this forms the upper pitcher 
margin (Fig. 11). This is a repetition then of the condition of 
Nepenthes lid, and the two only differ in the relative width of 
their attachment to the midrib which gives origin to them. But 
T 
