Kerr — Dischidia rafflesiana and t)ischidia numnmlaria. 295 



different localities vary in this respect as tliey do in others. l*"or instance, 

 Scott and Sargant have noted differences in the structure of the root, and the 

 proportion of stomata on the inner and outer surface of the pitcher, in plants 

 from Burma and Java.' Occasionally young plants with only llat leaves 

 have dorsal roots, in which case these roots grow towards the support, and, 

 like the ventral, act as attaohing-roots. 



Twenty or more closely crowded pitchers may be produced on one branch; 

 but at some time or another from this brancli spring one or several twining 

 shoots whicli climb with a sinistral twist up the branches of the host-tree. 

 These twining shoots, which iiave very long internodes, bear the third form of 

 leaf — the ordinary foliage leaf — which is considerably larger and thinner than 

 the leaves of the seedling ; it is very caducous. The twining shoots have 

 adventitious roots at the nodes, and frequently also scattered along the 

 internodes. The lateral branches of these shoots bear pitchers. Eventually 

 it may happen that most of the branches on a large tree carry one or more 

 groups of pitchers of the epiphyte, all the groups being connected by the now 

 leafless twining shoots. 



The pitchers, ■ as I have already mentioned, have their base, with the 

 entrance to the interior, turned towards the support, and pressed close against 

 it. According to their position on the branch, the pitchers may have any 

 direction, from pointing straight downwards to pointing straight upwards ; 

 in the former case it is hardly correct to describe them as pendulous — a term 

 which conveys the idea of hanging loosely and swinging; whereas they are 

 always— in the first instance at least — firmly fixed. Sometimes a group of 

 pitchers, owing to the weight of their contents, may become partially detached 

 from a branch. 



It has been noted that D. rafflesiana prefers to live on decaying trees, and 

 certainly it is frequently to be seen on dead branches ; but dead branches are 

 common on Dipterocarpas Uiberculuiun, whether this tree is the host of a 

 Dischidia or not. After examining a number of trees, I came to the conclusion 

 that, on the wJiole, dead branches were more frequent on those trees which 

 carried either U. rafflesiana or D. nunimukiria. 



The histology of the vegetative organs of D. rafflesiana is considered very 

 fully in papers by Scott and Sargant', and Groom-, and need not be gone 

 into here. The tissues of the leaf of I), nummularia resemble those of the 

 foliage leaf of D. rafflesiana ; the greater part of the leaf is composed of thin- 

 walled water-tissue cells; there is no palisade parenchyma, the tissues of the 

 upper and lower surface being similar. In tlie ordinary form of the leaf the 



' Suott and Sargant, he. oil. 



' Groum on Disc/iidid rafflesiana (Wall.), " Annals of Botany,'' vol. vii, No. xvi, 1893. 



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