2x6 Yapp . — Two Malayan ' Myrmecophilous ’ Ferns. 
this protection is purposely utilized by man. For instance, 
the Chinese of Canton, who cultivate orange-trees in large 
groves, connect the trees together by means of long bamboo 
staves, so that the tree-dwelling ants may readily travel from 
tree to tree, and thus prevent the ravages of insect pests. 
In many instances the relations between ants and plants 
are without doubt of a merely casual nature, to which no 
special biological meaning is to be attached ; but these chance 
alliances may on the other hand, when mutual benefit results, 
lead on to such cases as those of various species of Cecropia , 
in which, as shown by Schimper, the adaptation would seem 
to be truly reciprocal 1 . 
As, in the numerous cases of so-called myrmecophily, 
different parts of plants, plants of different genera and orders, 
and ants of different genera are concerned, Professor Bower 2 
suggests that the origin of the inhabited hollows and the 
question of the mutual advantage derived from the symbiosis 
should be considered independently in each case. It is, more- 
over, desirable to collect all available data regarding the food 
and habits of the ants, and the homes inhabited by the 
different species. 
Dr. August Forel has very kindly undertaken the identi- 
fication of the ants found in the two species of P olypodium. 
The ant inhabiting the material of P. sinuosum from Singa- 
pore proved to be Technomyrmex albipes , Smith, which belongs 
to the sub-family Dolichoderinae 3 . That found associated 
with P. carnosum is a new species of Cremastogaster , C. Yappi , 
Forel 4 . In addition to the ants, an egg-capsule of a species 
of cockroach 5 was discovered in the galleries of P. sinuosum , 
1 Schimper (’88). Buscalioni and Huber (’00) have recently arrived at rather 
different conclusions from those of Schimper, i. e. that the ants have taken to live 
in the Cecropias, not in quest of food, but in order to get a nest above flood level. 
2 Bower (’87), p. 320. 
3 Forel (’94), p. 496, states that most of the species of this group keep no plant- 
lice, but lick up secretions of plants, or else live on insects. 
4 Forel (’01), p. 374. 
5 Goebel (’89), p. 208, states that cockroaches were found by Guppy in the 
chambers of a species of Hydnophytum ; but the galleries of P. sinuosum are small, 
