14. The First Architects
I SUPPOSE every investigator of termite classification or behaviour must at one time or another have been dumbfounded by the ambitious nature of their building and engineering operations. The mightiest structures man has built on this earth; the Pyramids of Egypt, London's Underground system, New York's skyscrapers, the Simplon tunnel, the biggest cathedrals, the longest bridges, these, compared with works of the termite, taking into consideration its size, are as mole-hills compared with mountains.
Wilhelm Böche, in Der Termiten Staat, made some calculations to show how the work of man compares with that of the termite. Taking size into consideration, man would have to erect a building as high as the Matterhorn, that is 14,760 feet, if his work was to be equal to a termite tower forty feet in height, such as is often found in Africa. Such was the estimate of the German writer. It is not the size of the termitary only, however, which amazes the investigator, but the almost incredible extent of their underground activity.
I have already described at some length their vertical boreholes, those mighty feats of engineering which they have been forced to carry out in their ceaseless struggle against drought. They are forced to penetrate the bowels of the earth in their eternal search for water, which they have to convey drop by drop in order to keep their large communities from death. The actual depth of these shafts we do not know; the one I have mentioned before was deeper -- exactly how much deeper is uncertain -- than sixty-five feet.
I want to give an account of some facts which came to my knowledge when I made a journey through the valley of the Limpopo and the Lowveld of Zoutpansberg a few years ago.
It was during this journey that I came to a real appreciation of the astounding genius for building which the termites possess. Everyone who is interested in the termite will have read and probably seen photographs of the enormous termitaries which are found in tropical parts of Africa. In the Lowveld of Zoutpansberg I found some giants, nor were these the exception by any means. In some parts of the Limpopo valley these gigantic termitaries are a very usual feature of the landscape. An engineer friend of mine, Norman Hugel, carefully measured and calculated the weight of earth making up one colossus, and found that it consisted of eleven thousand seven hundred and fifty tons of earth. This termitary belonged to a small Eutermes. Just think of it, eleven thousand seven hundred and fifty tons which had been piled up grain by grain, for Eutermes never uses mud for building purposes. They use only microscopic grains of sand; every one is rubbed clean and polished before being coated in a sticky cement, then every tiny stone is carefully placed in the right place. So grain by grain, the termites heaped up a structure weighing eleven thousand seven hundred and fifty tons. One would imagine it to take thousands of years to accomplish, but it was hopeless to try to estimate the period of time. There is no doubt that it was a matter of centuries. There is yet another mystery connected with this particular activity of the termites, which I cannot recollect ever to have been mentioned by other observers. The riddle is simply this: From where does the enormous mass of earth come? One would expect to find a hollow cavity below such a vast excrescence; a hollow in the earth corresponding in size to the superficial mass, because there is no doubt that all the building material is carried from below. No signs of any cavity have ever been found, however, notwithstanding the fact that many of the giants have been intersected in many parts of Africa and have even been totally demolished for purposes of road-making, railway lines, house building, dams, aerodromes and all the many activities to which civilized man is prone.
For instance, in order to level the surface of the Bulawayo aerodrome, alone, twenty thousand tons of 'ant-heap' were carted away. In all such cases, especially for purposes of making railways, dams or heavy buildings, the ground is always carefully tested for cavities after the surface termitaries have been removed; yet no hollows corresponding in size to the superficial structures have ever been found. Yet we know that the building material of the termites must come out of the earth.
The reader will remember how I discovered the source of the termite water supply by sheer chance after it had been to me for many years such an unsolved problem that I had come to the conclusion that the insects manufactured water from hydrogen and oxygen.
I believe now that if I had given the matter more thought and reasoned more clearly, these giant termitaries with no cavities below them would have led me to the truth. In the first place millions of gallons of water were necessary to build these structures, and a further inexhaustible supply for the needs of the termites themselves and the internal economy of the vast termitary. A quite considerable stream of water must flow into the nest day and night to keep alive the community. The explanation stares one in the face: Both water and building material come from innumerable tiny cavities in the earth, which the termites are constantly increasing, for the purpose of enlarging the termitary and their water supply as the community grows. It seems a kind of vicious circle.
In another instance I found a rocky kopje or hill in the Sabie Valley, which consisted of one vast termitary belonging to the much-feared Macrotermes bellicosus, the Fighting Termite. The bite of the bloodthirsty soldiers of M. bellicosus goes deep enough to cause considerable bleeding. One of these soldiers I took back to Pretoria with me and managed to keep alive for a week after his separation from the nest. He could bite right through the wood of a matchbox with a crunch which was distinctly audible at a distance of four or five yards. This termitary, comprising as it did a whole kopje, caused me a great deal of mystification. I simply could not accept for one moment the notion that the huge rocks on its summit had been heaved up by the building operations of the termites. It is true that Dr Preller and I found stones weighing ten and twelve pounds high up in the termitaries of Eutermes at Pelindaba, which could only have got there through elevation by the termites. But on the kopje were rocks hundreds of tons in weight. Every inch of ground between and under these rocks consisted of the pebble-built structures of M. bellicosus. The probable solution was that the termites had first removed all the original earth between the rocks and then substituted their own pebble work.
I had never seen anything like this occurring, however, and the question of what they had done with all the original earth still remained. For there was no sign of normal earth.
I have mentioned this case merely as an illustration of the countless insoluble problems which constantly confront the investigator.
During this journey I took the opportunity of doing some experiments to find out in what way and how far magnetism affects the termite. Mr Piet Haak of Pretoria kindly lent me a dozen of the strongest steel magnets obtainable. I speedily became convinced, however, that my magnetic field was too weak. To come to any certain conclusion, a powerful electromagnet would have to be used. I have no doubt, however, that the magnetic force of the earth influences the work of all termites. In this connection, one should remember the water shaft at Waterberg which had bends only east and west.
The 'Compass Termites' of Australia build their termitaries with the narrowest diameter towards the magnetic north. The late Mr Claude Fuller alleged that the summits of the termitaries of M. bellicosus always leant towards the true west.
In the Lowveld we established the fact that the termitaries of M. bellicosus were always narrower in one plane than the other. A straight line through the widest diameter always pointed true east and west. In the neighbourhood of these last-mentioned termitaries there was a palm tree of 160 feet in height. Quite by chance I found a covered-in termite runway going up the trunk, and vanishing in the foliage above. On investigation we found that this passage was used by Eutermes workers for the purpose of fetching water from the top of the palm to their termitary, which was sixty feet away from the foot of the tree. I took the opportunity during this time, too, of studying the art of the Eutermes builders in more detail, and while observing the building I found the subject of nutrition constantly looming large. Claude Fuller and other famous observers call Eutermes the Haymakers, and take it for granted that the grass collected by these termites is used for food. When one examines a termitary belonging to Eutermes, one finds that many passages are filled with dry grass stalks of about half an inch in length. This grass is carried to the termitary at night through passages which spread out in all directions. At intervals in these passages there are storerooms where some of the grass is carefully stowed and even actually inside the termitary there are sometimes parts filled to such an extent with grass that there is barely room for soldiers and workers to pass. 'Food' says my friend Claude Fuller and 'Food' bay the other observers, without any doubt arising in their minds.
It must be food, they decide, because such a large quantity is stored and so much of their activity is centred on collecting it. There could have been no other basis for their conclusion, though no one has ever seen Eutermes eating grass, nor has anyone found grass within the body of the termite.
I myself threw this theory overboard many years ago. I convinced myself by microscopic examination that Eutermes was not equipped for chewing grass and swallowing it; I doubt very much whether the worker could do this. Its mouth parts certainly are more developed than those of the soldier, but this development is directed towards special functions -- the conveyance of grains of sand, coating them with sticky fluid, the feeding of fluids to the queen and the larvae, and severing grass stalks. But they are quite incapable, it seems to me, of masticating and swallowing the latter. Another reason which made me question the food theory was because I never succeeded in finding under the microscope the least sign of grass in the entrails of the workers or soldiers. All that I found was a fluid which had every appearance of being derived from the moisture of the earth and the sap of plant roots.
Later I learnt of certain observations in South America which strengthened my conclusions. I have mentioned before that the habits of ants and termites are often so much alike, that the behaviour of one affords a key to the behaviour of the other.
Eutermes workers building an arch by gradual approximation of two pillars.
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In South America and Mexico there is an ant known as the leaf-cutting ant, which does great damage to trees by cutting round pieces from the leaves. These they drop to the ground where other workers are waiting to pounce on them and bear them to the nest. Without any further investigation, it was assumed that these leaves were used for food. Recently, however, an observer in Mexico proved that the leaves are never used for feeding purposes. Instead they are packed in masses on the side of the nest where the heat of the sun is most fierce. The theory of this observer is that the leaves serve the sole purpose of protection against the rays of the tropical sun. Whether this is so, we cannot say, but at all events the leaves are not eaten and do not serve as food. I then wondered whether Eutermes might be using grass for the same purpose. I soon realized, however, that this could not be the case, for the method of storing would not enable the grass to serve as a protection.
Now all the architecture of Eutermes is based on the arch. Probably they were the first architects to discover the secret of arch building. It took years of civilization before man discovered how to use the arch in architecture. Those mighty builders, the Egyptians, knew nothing of the arch and limited themselves to two vertical pillars with a colossal stone as crossbeam. The Greeks and Romans did not understand the properties of the arch. It was only in the Middle Ages that architects came to understand fully the value of the arch in building.
Eutermes workers building an arch. In this case a grass stalk is laid from pillar to pillar, and covered with tiny pebbles.
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It is very interesting to note that we find in the architecture of the termite two stages of development of the arch, analogous to that in human architecture.
Let us return to Eutermes and examine some new building operations after rain has fallen. One portion of the termitary has a dark stain. If we examine this with a magnifying glass we find that it is a wet patch where the outer crust has disappeared. It is possible to cut away a small piece of this without causing enough disturbance to make the workers disappear.
Now we can, examine the building of the first architects of this earth. We see that all the building of Eutermes is based on the arch. This arch is formed in two ways; the first and most primitive is made by inclining two vertical pillars towards each other until they meet. This is the way man, too, made his first arch. But about every eighth worker carries in his mouth a grass-stalk instead of a pebble. He ascends one of the pillars, quickly fastens one end of the stalk with sticky fluid to the top of the pillar, and then rushes away without waiting to see what happens. This is what does happen: the grass-stalk sinks slowly towards the other pillar until its end comes to rest on the summit. There we see another worker waiting in readiness. As soon as the end of the stalk comes within his reach, he stretches up, grips it, and pulls it down to the summit of the pillar where he in turn attaches it with fluid. On this crossbeam the termites plaster tiny pebbles until a perfect arch results. Success is by no means always inevitable. Occasionally the stalk remains vertical instead of sinking down. In these cases the termites simply finish the arch by inclining the tops of the vertical pillars towards each other until they meet, while the stalk is eventually covered with masonry. Why the stalk is used at all when the termites are able to finish the arch with pebbles only, I cannot tell. Perhaps it is only a rudimentary remainder of a principle which has disappeared. Whatever may be the explanation, I am positive Eutermes never uses the grass-stalks as food.
Next: 15. The Queen in her Cell
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