Taking things all round, my men behaved very well, but these were moments of the greatest anxiety for me, and I myself was praying fervently to God to get us out of that difficulty. My strength was failing more and more daily, and although I was suffering no actual pain, yet the weakness was simply appalling. It was all I could do to stand up on my legs. What was worse for me was that my head was still in good working order, and I fully realised our position all the time.
The country we were travelling over was fairly hilly, up and down most of the time, over no great elevations. We passed two large tributaries of the main stream we had found before, and a number of minor ones. The main stream was strewn with fallen trees, and was not navigable during the dry season. The erosion of the banks by the water had caused so many trees to fall down across it that no canoe could possibly go through.
I noticed in one or two places along the river traces of human beings having been there some years before.
In the afternoon we again wasted much energy in knocking down two palm-trees on the summit of which were great bunches of coco do matto. Again we had a bitter disappointment. One after the other we split the nuts open, but they merely contained water inside shells that were much harder to crack than wood. My craving for food was such that in despair I took two or three sauba ants and proceeded to eat them. When I ground them under my teeth their taste was so acidly bitter that it made me quite ill. Not only that, but one sauba bit my tongue so badly that it swelled up to a great size, and remained like that for several days. The entire genus of the Sauba (Œcodonia cephalotes) ant is typical of tropical South America. The largest Sauba is about an inch long, and possesses powerful scissor-like clippers, with which it can destroy any material, such as leather, cloth, paper or leaves, in a very short time. Their method of work is to cut up everything into circles. I remember one day dropping on the ground a pair of thick gloves. When I went to pick them up I found them reduced to a heap of innumerable little discs—each as large as a sixpenny coin. It is with those powerful clippers that the Saubas, having climbed in swarms up a tree, proceed to despoil it of its foliage. The work is done in a systematic way, each ant quickly severing one leaf and carrying it down, banner-like, vertically above its head, tightly held between its strong mandibles.
It is this habit of the Saubas which has brought upon them the Brazilian name of Carregadores, or carriers. One sees everywhere in that country long processions of those destructive insects, each individual marching along quickly with its green vegetable banner, sometimes eight or ten times its own size and weight. In many cases the Saubas working aloft cut the leaves and drop them on the ground, where other carriers are waiting to convey them away. So numerous are the Saubas that in the forest one can hear distinctly the incessant rustling sound of their clippers at work. The Saubas use the leaves in order to construct thatched waterproof roofs over the domes and turrets at the entrances of their extensive subterranean galleries, which would otherwise become flooded during the torrential rains prevalent in those latitudes. The roofs are constructed with wonderful skill, each leaf being held in its place by granules of earth. The galleries, of immense length and much ramified, are often as much as 10 to 15 cm. in diameter. The entrances to them are usually kept blocked, and are only opened when necessary. Above ground the Saubas make wonderful wide roads, thousands of which can be seen everywhere in the forest, and upon which endless processions go by day and night. The workers of the Saubas can be divided into three orders not very clearly defined, as units of intermediate grades are constantly met. The largest of those workers possess extraordinarily massive, double-humped heads, highly polished in the case of members which are visible on the surface, and dull and hairy in the giant fellows which spend their lives within the subterranean passages. These hairy Saubas display a single frontal eye—not found in any of the other Saubas, and, as far as I know, in no other kind of ant. They never come to the surface except when attacks are made upon the galleries. Great excitement is shown in the colonies when the winged ants, of extra large size—especially the females—start out on their errand of propagating the race.
The workers with polished heads—fierce-looking brutes—do very little actual work, but seem to be the superiors and protectors of the smaller workers. In every case the body of all orders of Saubas is solidly built, with the thorax and head protected by spikes.
Much as I disliked the Saubas for the endless trouble and suffering they inflicted upon me, I could not help admiring their marvellous industry and energy. No agriculture is possible where the Saubas are to be found, and even where they do not exist in Central Brazil, if agriculture were started they would soon invade the territory and destroy everything in a short time. Foreign plants do not escape. No way has been found yet of extirpating them.
