32 
rorULAK SCIENCE KEY IEW. 
a slaty-gray colour ; and the galleries with which they are inter- 
sected in all directions are lined by the ants with a thin papery 
material. 
The allied genus Hydnophytum , which differs from Myrme- 
codia in having a smooth tuber and small deciduous stipules, 
was also figured and described by Kumpf (as Nidus germinans 
formicarum nigrarum), and named and redescribed by Jack at 
the same time as Myrmecodia. In the structure of the tuber 
and its mode of use by the ants, it seems very similar to Myr- 
mecodia , only that the best known species, H . formicarum , is 
inhabited not by red but by black ants. Three or four species 
are described, natives of Tropical Australia, the Fiji Islands, and 
the Indian Archipelago. 
Passing now to those trees, the trunks and branches of which 
are used as habitations by ants, the most remarkable are those 
belonging to the South American genus Triplaris , all or nearly 
all the species of which are described by Meisner in Decan- 
dolle’s Prodromus as u arbores ramulis fistulosis formicis hospi- 
tium prsebentibus.” Aublet, in his “ Histoire des Plantes de la 
Gruiane Fran^oise,” published in 1775, figures and describes a 
species (doubtfully referred by Meisner to T. surinamensis, 
Cham.) under the name of T . americana , of which he says: 
“ Ants are found in abundance in the interior of the trunk, 
branches, and twigs of this tree, in such a manner that* when 
one strikes or cuts it, one is soon quite covered and acutely tor- 
mented by them, an accident which I myself have experienced. 
The only means by which one can get rid of them is to plunge 
oneself in water.” Triplaris is a genus of Polygonacece , form- 
ing with Ruprechtia and the monotypic genus Podopterus the 
sub-tribe Triplaridece ; it is characterised by the remarkable 
shuttlecock-like appearance of the fruit, an appearance caused 
by the three outer lobes of the perianth growing out into erect 
membranous wings, and reminding one very forcibly of the 
fruits of Dipterocarps. The most detailed account of the ant 
which infests these trees is that given by Weddell,* who 
says : — 
“ The trunk, the branches, and even the smallest branchlets 
of the species of this genus are hollow, and serve as habitation 
to a peculiar species of ant, which gives off when excited a 
somewhat agreeable scent, resembling that of the Gicindelece . 
If one happens to touch the trunk of a Triplaris accidentally, 
especially if it is shaken, the ants rush out by hundreds from 
the interior of the tree through the small canals by which the 
medullary canal communicates with the exterior, and if escape 
is not made as quickly as possible one is covered with these 
* u Ann. Sc. Nat. (Bot.),” 3rd series, xiii. 262 — 267. 
