Yapp.— Two Malayan ‘ Myrmecophilous ’ Ferns . 193 
and that the leaves are long-lived, being formed only at com- 
paratively long intervals. It might perhaps be expected 
that young leaves would be formed chiefly at certain periods 
of the year, but it is curious to note that the specimens of 
P. carno-stim collected by myself were found in December, 
towards the close of one of the rainiest periods of the year, 
while the material of P. sinuosum sent me by Mr. Ridley, 
which appears to be equally devoid of immature leaves, was 
collected in March, soon after the commencement of rainy 
weather, which had been preceded by an unusually long spell 
of drought 1 . 
The description of the external features of Polypodium 
carnosum as given above is taken from the specimens collected 
on Gunong Inas ; those from other mountains in Perak are 
precisely similar. The description given by Burck 2 of J avanese 
specimens differs only in a few unimportant details, but the 
specimens from other parts of the Malay Archipelago, which 
include Blume’s types, differ somewhat more extensively. 
These differences will be discussed at greater length in the 
section devoted to systematic position. 
Internal Structure. 
A. Rhizome . A cross-section through an old stem reveals 
the presence of an extensive system of hollow spaces in the 
ground-tissue (Figs. 14 and 1 5). These are the ant-galleries. 
If they are followed towards the apex of the stem, they are 
found to be replaced in the younger parts by a fragile, 
large-celled, thin-walled tissue, which by breaking down gives 
rise to the galleries : the latter are therefore of lysigenous 
origin. 
Externally the rhizome is coated with a thin layer of wax, 
while on the dorsal and lateral surfaces, in the young parts 
at least, are small scattered epidermal hairs, one of which is 
1 Although some periods of the year in the Malay Peninsula can usually boast 
a considerably greater rainfall than others, there are no well-marked wet and dry 
seasons, the climate being more or less hot and moist all the year round. 
2 Burck (’84), p. 96. 
