266 Scott and Sargant. — On the Pitchers of 
From a physiological point of view, we can only say 
that those roots of Dischidia rafflesiana which have internal 
phloem, are showing a tendency to become fleshy, as is 
indicated by their irregularly swollen form. These roots 
are evidently becoming adapted for the storage of proteids ; 
whether the material for these proteids is derived from the 
humus in the pitchers, or from the tissues of the plant itself, 
it is impossible to say. The structure of the internal phloem 
is perfectly normal, and is identical with that of the external 
phloem in the same root. 
Medullary phloem has, we believe, so far only been recorded 
in the genera Cucurbit it, Vinca, Strychnos, Chironia , and 
Lythrum 1 . It therefore seemed worth while to describe this 
new case of so exceptional an anatomical feature. Medullary 
phloem in the root has always been found to be a very incon- 
stant character. Strands of phloem in the wood of roots are 
less uncommon and somewhat more constant when they 
occur. 
Conclusions. 
If we now endeavour to sum up the results of our work on 
the pitchers of Dischidia rafflesiana , we find that as regards 
the morphology, there is no difficulty. Treub’s view is com- 
pletely confirmed by the study of the anatomical structure. 
The pitcher is a modified leaf, formed by great intercalary 
growth of the whole region between petiole and apex, the 
morphologically upper surface growing more rapidly than the 
lower. The outer surface of the pitcher therefore represents 
the upper surface of the leaf, and the inner surface of the 
pitcher the lower surface of the leaf. 
As regards the physiology, we can only be guided by the 
structure, as, under the artificial conditions of cultivation, 
experiment was out of the question. 
There are no structural features whatever which lend the 
1 See Scott and Brebner, Internal Phloem in Root and Stem of Dicotyledons, 
Ann. of Bot. vol. v. 1891. For Lythrum see Fremont, Journal de Bot. t. v. 
1891, p. 448. 
