IN BORNEAN FORESTS [chap. 



species, which is widely spread in Southern Asia and Malaysia, 

 not possessing any substance that could be used to bind together 

 the leaves required to form their nest, have found the way of utilising 

 for that purpose a kind of silk which their own larvae secrete for 

 making the small cocoon in which they shut themselves up for 

 undergoing their final metamorphosis. To effect this several adult 

 (Ecophylla hold in their mandibles one of the larvae, and oblige it 

 to drop from its mouth on the edge of the leaf, kept in the required 

 position by other ants of the same family, the coveted gelatinous 

 thread. Thus the silken filaments which ought to serve the larvae 

 for making their own cocoons are used by the adults of the colony 

 for tying together the materials for building the house of the com- 

 munity, precisely as we might act ourselves towards a mature silk- 

 worm or spider, holding it between the fingers and obliging it to 

 emit the silky thread wherever we desire it to be. Few examples 

 reveal the high intelligence of the ants more strikingly than this. 



At Marop I found several species of honey-producing Hymenop- 

 tera (Trigona) abundant. They are like very small bees, but unpro- 

 vided with a sting, and make their nests with a sort of resin under- 

 ground. Their Malay name is Clulut. One day I set patiently to 

 work to dig out one of these nests belonging to Trigona apicalis. 

 Its entrance was a small cylindrical canal about the size of my little 

 finger, which penetrated the ground amidst the roots of a dead tree, 

 projecting about three or four inches from the soil. 1 The canal 

 led into a subterranean cavity about six inches in diameter, com- 

 municating with several irregular chambers all formed of resin. 

 From the central chamber ramifications extended, supporting a large 

 number of pyriform or spheroidal soft waxy cells, which contained 

 the larvae. These cells, which filled the entire cavity, were loosely 

 connected together, and attached to the walls of the ramified cham- 

 bers like the berries in a bunch of grapes. They appeared to me to 

 be of two kinds, some darker than the others. Some only contained 

 sour honey : in others were the larvae. In this nest the best honey 

 was nearly used up, and I imagine that it must have been stored 

 in big cells of a special kind in the secondary chambers. A few of 

 such cells, in fact, remained. They measured about half an inch in 

 diameter, and were irregularly grouped together, and fixed to the 

 sides of the chamber by a common peduncle. The honey they 

 contained was clear, liquid, and slightly sour. Notwithstanding all 

 my care, the nest broke in digging it out, which prevented a more 

 complete investigation. 



The nineteenth of April was a very hot day. The ther- 

 mometer in the sun rose to 130° Fahr., and on the following day 

 we had incessant rain. On the twenty-eighth of April, Atzon, 



1 In some nests this canal, which is a tube entirely formed of resin, is 

 twice as long in its external projecting portion. 



162 



