250 Scott and Sargant.— On the Pitchers of 
The mesophyll bordering on the inner surface of the pitcher 
is the only tissue in the plant which appears to be especially 
adapted to transpiration. This fact is correlated with the 
distribution of the stomata, as we shall see below. 
The layers next the inner surface of the pitcher contain a 
purple pigment, which was very slightly developed in the 
comparatively young pitchers formed at Kew, but was very 
abundant in pitchers of the same plant which had been already 
formed in Java and were about two years old. It was also 
very conspicuous in full-grown pitchers from other sources. 
No such pigment is present in the foliage-leaves. 
Bands of thick-walled, but unlignified sclerenchymatous 
fibres accompany the bundles of both pitcher and leaf, chiefly 
on the inferior side. They form a sheath, crescent-shaped as 
seen in transverse section, enclosing the normal phloem. 
Some of these fibres straggle off, as it were, from the bundles, 
sometimes singly, sometimes two or three together, and 
traverse the mesophyll in all directions. The fibres of the 
mesophyll therefore, are not isolated idioblasts, but are always 
continuous with the sclerenchyma of the bundle-system. 
The sclerenchyma is better developed in the pitcher than in 
the leaf. 
Laticiferous cells extend into the mesophyll of both leaf 
and pitcher. They are much more abundant in the latter 
than in the former. In the leaf indeed they are so scanty 
that the latex is scarcely noticeable when the leaf is cut, 
while in the pitchers, and especially in the older ones, it 
spurts out as soon as the knife pierces the tissues. The main 
laticiferous tubes are found in the mesophyll above and below 
the midrib, and their principal branches traverse the middle 
layers of the mesophyll throughout the lamina. Numerous 
minor branches are sent out towards both surfaces, but they do 
not seem to accompany the finer bundles. In the pitcher the 
outer surface is much better supplied with laticiferous tissue 
than the inner. Some attempt was made to estimate the 
relative frequency of the tubes in the two regions. Branches 
were met with about twice as often within eight cells of the 
