190 Yapp, —Two Malayan ‘ Myrmecophilous ’ Ferns. 
whole, almost every crevice of which is filled up by the growth 
of some branchlet or other. The mass thus formed may 
acquire a thickness of 10 or more cm., and as it completely 
encircles the branch on which it grows, the total diameter 
may reach, in the case of old plants, and depending of course 
on the thickness of the supporting branch, upwards of 30 cm., 
with a length of several times as much. 
In the living state the younger portions of the stem are, in 
the specimens I have seen, of a pale greenish-yellow colour, 
though in Burck’s figure 1 they are represented as being a very 
decided green. The older parts are black and apparently 
dead. Thus, as the plant grows, the mass may come to 
consist of a number of living plants, isolated by the dying- 
off of the older parts behind, but still connected together 
by these persistent, apparently dead parts 2 . That the oldest 
parts of the rhizome in such a mass are really dead, even 
when few visible signs of decay are present, is, I think, a fact, 
though the stem, or parts of it, may undoubtedly continue to 
live for a considerable time after the blackening process has 
set in. This is proved by the following facts : first, that 
living and healthy leaves may be present on parts that have 
become perfectly black, which shows that the vascular bundles 
at least are still living ; and secondly, one occasionally finds 
small greenish knobs of living tissue isolated amongst com- 
pletely blackened parts (a, a , Fig. 6). These occur in the 
position where lateral branches normally arise, and are, in fact, 
incipient branches which have either developed unusually late, 
or have lain dormant during the further growth of the parent 
branch. 
In both the above cases the living parts, whether leaves 
or incipient branches, are never very remote from the apex, 
but are only found on parts of the rhizome near the young 
growing portions. 
(0) Leaf. The fronds are dimorphic, the fertile ones being 
1 Burck (’84), Plate VII. 
2 This condition of things is somewhat analogous to that found in a branched 
colony of corals. 
