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9 The Termite Queen as the Brain of an Organism
I recently had an opportunity - the like of which had never occurred before during my twelve years' experience in the study of white ants - to observe the queen inside her cell, surrounded by the usual workers. All observers, I think, experience supreme difficulty in observing the queen under normal conditions when studying these singular insects. The termite has such an abhorrence of light that it is almost impossible to reach the royal cavity without disintegrating the entire community and putting an end to all normal behaviour. In 1930, the Municipality of Pretoria decided to clear a house of white ants after an infestation that had lasted several years. Repeated efforts had been made to get rid of them, always unsuccessfully. On this occasion, however, the floors of the three lower rooms were broken up and all the insects' nests were destroyed. However, it was found every morning, after a clearance had taken place the previous day, that the termites had renewed a considerable part of their fortifications and were again hard at work. All efforts to find the queen had failed. I offered to locate her for the men in charge of the work if they would allow me two days to observe her after the cavity had been reached. They consented. I had the ground in the dining-room cleared and swept and soon traced three main arterial galleries. Taking the general direction of these three, I marked the point of intersection as the locality of the queen's cavity. This was situated underneath the fire-place. A little digging convinced us this was the right spot. The artist assisting me and I then took matters in hand. We made a gradual approach to the cavity, causing as little disturbance as possible under the circumstances.
The locality chosen for the residence of the queen was fortunately extremely dark and we had to employ an electric torch in our work. When we reached the outer walls of the cavity, I softened the cement-work by drenching it repeatedly with a gentle spray of water. When it was quite moist we sliced away the outer wall with a sharp knife until the hollow itself was disclosed. By means of occasional flashes from the torch we located the queen's cell in the centre of the cavity. We could see that up to the present we had occasioned very little disturbance. The work of the egg-carriers and feeders seemed to be proceeding normally. The opening of the queen's cell itself was a far more delicate operation and took several hours to accomplish, but even here we were eventually successful. We cut away more than half of the thick cell enveloping the queen. After that we kept her under constant observation for more than two days. The watch had to be maintained night and day, since the termites, unlike all other creatures, never sleep; never even rest for any appreciable time.
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We found the queen surrounded, first of all, by a circle of the larger class of soldier. These so-called ‘body-guards’ stood in line with heads turned away from the queen and were separated by equal distances throughout the circle. One remarkable fact was that on the far side of the cell the line of ‘bodyguards’, instead of occupying the floor of the cell, clung upside down to the roof, with their heads, in this instance, turned towards the queen. That is to say, the heads of the soldiers throughout the circle were all turned due north. I consider this to be of importance, because I am more than ever convinced that the magnetism of the earth is unquestionably a directing influence in the behaviour of termites generally. The plane of the circle was turned to the surface of the earth at an angle of about forty-five degrees.
The guards were generally absolutely motionless, but occasionally one of them would start swaying its head from side to side with its jaws widely distended. This movement was gradually imparted to the rest of the line until it had gone right round the circle, ending with the soldier next to the one that originated it. The cell was always crowded with the smaller class of worker, too. These were very tiny when compared with the big soldiers and the larger workers. It was soon evident that the small workers were engaged in three different kinds of labour. The largest number were busy carrying off the eggs laid by the queen. The eggs were being produced at the rate of about fifty thousand per day. This number will give some idea of the dense throng of tiny workers ceaselessly engaged in this work. A smaller number were feeding the queen. We saw nothing but fluid ever passed to her. As the worker approached the jaws of the queen, a tiny globule appeared at the apex of its rudimentary jaws. The little worker had to raise its body almost into a vertical position in order to reach the queen's mouth. Each drop was immediately absorbed and the work proceeded with incredible speed. There was always a queue extending far beyond the aperture in the cell, almost an inch in breadth. As soon as a worker had passed its drop of moisture to the queen, it marched round her on the far side and, circling her huge body, approached the exit from the side opposite to that by which it had entered. This meant that the food-carriers never obstructed each other and the work proceeded with machine-like smoothness. The same fact was also observed in the case of the egg-carriers.
The third labour undertaken by the small workers, the purpose of which was much more difficult to understand, gave us a lot of trouble. Their activity seemed to be that of ‘masseurs’. They climbed on to the body of the queen and appeared to be cleaning her skin. It has been assumed by other observers that this is, in fact, the sole purpose of their labour - to keep the skin of the queen clear of exudation. I doubted this from the very beginning, and what we observed now confirmed a theory that had occurred to me more than ten years before and when I had not had the opportunity of so closely observing the
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‘masseurs’. I noticed now that the ‘masseurs’ which entered the cell were practically empty of any ventral content, while those that left were filled to their utmost capacity with a colourless fluid. I had no longer any doubt, after I had examined a number under the microscope, that these ‘masseurs’ filled themselves from the fluid inside the body of the queen. How they managed to get it through the tough integument without injury to the queen, I do not know. It will be seen later on that the ‘king’ who was always present in the cell, could do the same thing - that is, fill himself with fluid from the body of the queen through her skin.
We were now faced with the puzzling question: What did the ‘masseurs’ do with this fluid which they collected from the queen? We followed one stream of them, carefully cutting away the termite-masonry guarding the galleries along which they travelled. Immediately below the royal cavity we found extensive fungus gardens. Here there were large numbers of etiolated termite babies of all classes. The theory which I had previously formed was confirmed by what we saw happening here. Each ‘masseur’, as it entered the fungus gardens, came into contact with a number of eager babies, and fed them in turn by passing globules of fluid from its jaws to theirs. This continued until it had literally been emptied.
It would seem therefore that, besides her sexual and psychological functions, the termite queen is also used as a store-room for the food-supply of the baby termites. It is very likely that the food stored in her body reaches a further stage of digestion, and it is quite possible that this feeding is not confined to the babies only. As stated above, we actually saw the king filling himself from her body in the same way as the workers did.
I had often been puzzled by the enormous size attained by the termite queen when compared with the rest of the community. I could never divine the actual benefit of this excessive growth. Her egg-laying activity certainly requires a capacious body, but not more than a third of her bulk seems to be involved in the work of egg-production.
The habits of termites and ants often resemble each other closely, and the queen termite in this respect resembles the syrup-storing ants of Mexico. In this species of true ant, one class is used for storing up the food-supply for the rest of the community. When the food-holders are filled to capacity, they resemble both in size and appearance the termite queen.
Before dealing with the most mysterious of all the termite functions which we observed in the queen's cell, namely, that of the ‘body-guard’, there are a few general phenomena I wish to mention:
Our common mentality enables us to recognize the more ordinary psychological manifestations in lower organisms. We can recognize clearly the expression of joy or happiness in all living things. The exultation which accom- | |
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panies the excitation of the sexual sense, fear and rage, love and hate - in fact, all the ‘basic’ mental states - are identical in man and in all living things below him in the scale of evolution. There is nothing more difficult to understand in connection with termites than the utter absence of what one has come to accept as elemental psychological constituents throughout the organic world. The first two termites emerge as perfect insects and apparently experience happiness or joy in being able to fly. But this condition lasts for a few minutes only. It may last for seconds only. They deprive themselves voluntarily of their wings and as speedily as possible re-bury themselves in the darkness of sub-terranean passages from which they never again emerge. If the white ant can experience no pleasure, it is thus incapable of feeling pain. If one touches the true ant or any of the higher insects with a drop of corrosive acid, one sees at once the contortions of supreme agony, differing in no particular from the behaviour of, say, a wounded lion. Most classes of termites show no reaction whatever even to so powerful a stimulus. The urge to self-defence or self-preservation in the individual is also entirely absent. The soldiers of Eutermes will occupy a post of danger where numbers are repeatedly killed without the slightest sign of fear or any attempt to save themselves by flight. I have seen one instance where a stream of water was turned into a nest. Thousands of workers hurried to the danger spot and tried unavailingly to stop the inrush by building a retaining wall. Hundreds of them were swept away repeatedly, but they continued this useless effort until the nest had practically been depleted of
workers. In a battle of true ants against termites the same behaviour can be observed. Soldiers occupy all the entrances to the threatened nest and allow themselves to be dragged out and slaughtered by the invading ants without ever making an attempt to escape. This also continues until there are no more soldiers to occupy the posts of danger. Above all, the great incentive and apparently greater reward afforded by the operation of the sexual sense in nature is absolutely wanting in the case of the white ant. In fact, there is no answer to the question: To what purpose? Why do they labour thus unendingly? What mighty incentive is there that compels them to perish in thousands in a cause from which the individual derives no benefit? One might assume that there is something in their mental make-up resembling the loyalty of human beings to a sovereign; but that assumption cannot stand. It is only a very small section of the community that ever comes into contact with the queen. The great mass of soldiers and workers not only never come into contact with her, but are generally separated from her by several yards of earth and rock. From birth to death they can never know of her existence through individual experience. If there is any sense of loyalty in the termite, it must therefore be directed to a being absolutely unknown to them.
Truly, their existence is a veritable death in life, without visible incentive or
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intelligible reward. Excluding the micro-organisms, of whose behaviour we know practically nothing, one would seek in vain throughout nature for similar conditions of life. The nearest analogous instance is the case of separate organs within an organism. There is nothing that the white workers and the red soldiers of the termite resemble so closely as the red and white corpuscles in the mammalian blood-stream. These, regarded as separate organisms, carry out identical functions in very much the same way. The corpuscles in the blood engage in highly complex purposive work directed in some mysterious way by the brain. So, too, the functions of termite soldier and worker are dependent entirely on the undisturbed presence of the queen. The moment she is destroyed all activity ceases, even in the outskirts of the nest, separated perhaps by as much as a hundred feet of earth and rock from the central cavity where the queen is kept, very much like the mammalian brain inside its thick bony protection. There are many other types of behaviour in the termite that can be explained only on the assumption that the entire community is a separate and self-contained organism working in all respects in the same way as the bodies of the higher mammals. In such an organism the queen is clearly the brain; the socalled fungus gardens are the digestive organs, where enzymes identical with those that digest the food in the mammalian digestive tract are secreted; while workers and soldiers represent the blood-stream circulating endlessly through the arteries of the nest and carrying out similar functions - conveying food to the digestive centres, providing sustenance for growing and living parts and repairing injuries. The mode of operation of the sexual sense in the termite community remains an inexplicable enigma until the observer comes to regard the community not as a congeries of individuals, but as a separate organism. Actual sexual excitement, such as one encounters in
all other organisms, takes place only during the flight of the two sexual classes. When this flight occurs, the entire community is thrown into a violent state of excitement. Rage, which is a common accompaniment of the sexual sense in nature, is then also apparent - and then only. Both soldiers and workers crowd around the entrance and attack anything that shows a sign of movement with bulldog-like tenacity. This is the only occasion that they appear in daylight in the open air. The flight of the two sexual individuals is not a ‘nuptial flight’ (as it is so often described) in any sense of the word. In fact, it is a very matter-of-fact affair from beginning to end. No contact between the sexes takes place while they still possess their wings, and not even after they have deprived themselves of their wings. It is only after they have reburied themselves in the earth that this contact occurs. It is then a matter of a few seconds, without any sign of the excitement that is common to all other creatures. This actual sexual contact is, in fact, the final incident in a series of occurrences the crisis of which was a manifestation of the community. After this brief contact, sexual behaviour never again occurs and
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the queen is fertilized for life. It must also be remembered that the male and female insects may be present in a nest for as long as two years after they have developed into perfect insects, wings and all, before a flight takes place. They are in perpetual contact with each other, but there is never the slightest indication of sexual behaviour as far as they, as individuals, are concerned until all these different steps have been completed. They must emerge into the open air; they must actually fly, if even for a few seconds only; the queen must send her mysterious ‘wireless’ signal into the air, they must deprive themselves of their wings and re-bury themselves in the earth, and it is only then that sexual behaviour, as far as these two individuals are concerned, occurs. If they are prevented from carrying out any one of these operations - if, for instance, they are prevented from flying and forcibly deprived of their wings - they will perish, although in contact with each other, without making any attempt to complete the series of events.
Although fear is never discernible in an individual, it is certainly an attribute of the community as a whole. In many species a very violent attack on the nest from without will cause a terror-stricken retreat of both workers and soldiers to the depths of their underground fortifications. So rage, also, is an attribute of the community and not of the individual. If the attack on the outworks is slight, the entire community may be thrown into a state of violent rage that is quite clearly discernible in the behaviour of the masses of both workers and soldiers.
It will thus be seen that all critical mental states - such as fear, the incentive to self-protection, anger and the excitation of the sexual sense - which we recognize as mental attributes of the individual in the case of all higher animals and insects, is in the case of the white ant entirely absent in the individual and is manifested only by the community as a whole.
This analogy between the life-history of a termite community and the different bodily functions of any of the higher animals can be observed in many other directions. The most mysterious of her functions, ‘the influencing at a distance’ of all classes of her ‘subjects’ by the queen, seems identical with some of the functions of the brain in higher animals. I established by many carefully devised experiments that all the communal work of the white ant is dependent upon the undisturbed presence of the queen in her cell. If the outer skin of a termite hill is partially destroyed, the workers repair the injury by working from different sides. There is a continual stream coming up through the arteries of the hill from below. Each one of these blind individuals hurries to the edge of the ‘wound’, carrying in its jaws a microscopic pebble. This it covers with a sticky mucilage by rolling it around between its jaws. The pebble is hurriedly placed in position and the worker returns to make room for the following one. There seems to be no deliberation and there is certainly no per- | |
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ceptible communication between the workers on one side of the ‘injury’ and those on the other side. In the case of some species it is possible to divide the ‘injury’ into two parts by driving a steel plate through the centre, so as to ensure a complete separation of the workers. Now, termites engage in many different kinds of building-work to repair an ‘injury’ of this nature. They construct arcs of different widths and sometimes they repair an ‘injury’ by constructing high turrets of different shapes. But, whatever building-work they engage in, it seems quite certain that the design is pre-determined. The blind workers on both sides of the steel plate, deprived of all contact or communication, work out an identical design, and when the repairing masonry reaches the plate, whether it be
an arch or a turret, the walls join up as if no plate separated them. Where is this pre-conceived design formed, and from where are the workers directed in its execution? It is quite certain that the continuance of the communal work is dependent upon the presence of the living queen in her cell, and it seems, therefore, fairly certain that both the design and its execution emanate from her.
In the human body repairs are carried out by the blood corpuscles in an identical manner. Even more strikingly similar is the work of the microscopic organisms which weave and build up bone. Here, too, there is a preconceived design, and both the design and the direction of its execution emanate from the brain, but there is no organic connection between the brain and these labouring organisms. The influence, whatever its nature may be, is ‘influence at a distance’.
To return now to the functions of the queen's ‘bodyguard’: I have noticed that it is a common thing for observers to attribute to an organism functions suggested by a name, even where the name is clearly a misnomer. The ‘lifeguards’ of the queen were so called because they resemble the guards which protect a human sovereign inside her palace. It was at once assumed that they were there to protect the queen from any hostile invasion. I have for many years doubted whether this was the actual function of the guards. For one thing, the queen is invariably placed in the deepest and best protected part of the nest. Before any enemy could reach her, it would have to traverse perhaps miles of intricate arteries, and in every inch of these arteries it would encounter soldiers who would attack such an invader à outrance; and, if it was small enough to travel through this system of arteries, it would have to fight a thousand battles for its very life before it could reach the queen. Should the invading enemy reach the royal cavity, the battle would be already won. If it had been triumphant thus far, no defence that a single line of soldiers round the queen could put up would save her from destruction. This consideration alone convinced me that we still have to search for the true functions of the line of ‘guards’ in the royal cavity. In the present instance, we found it was quite
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impossible to provoke a concerted attack by the ‘guards’ on one's finger, however much one pushed them about and disarranged their line. It was, in fact, very difficult to induce an individual to make use of its powerful jaws even where one's finger was thrust right up against it. On the outskirts of the nest, contact with one's finger immediately occasioned a concerted attack by all the soldiers in the neighbourhood, and everyone of this special species was able to inflict a painful wound with its powerful hooked jaws.
During the time we were observing the queen in her cell, an accidental occurrence revealed to us a very interesting and very remarkable fact in connection with the line of ‘guards’. While we were actually watching her - practically night and day - the termite work in the other rooms of the house continued undisturbed. If a piece of termite masonry was destroyed during the day, it was renewed during the night, and we invariably found the insects hard at work the following morning. In fact, no destruction of masonry ever occasioned a real cessation of the work of the community. On one occasion, however, a small piece of hardened earth fell from the roof of the queen's cell, the point of which dealt her a fairly hard blow about the middle of the body. The rest of the earth fell on a portion of the line of ‘guards’, destroying three or four of them and throwing the whole line into a state of disorder and extreme excitement. The only sign of shock, as far as the queen was concerned, was a rhythmic and unceasing movement of her head sideways. Within five minutes of the occurrence there was a remarkable series of events. Most of the ‘guards’ disappeared into the uninjured galleries behind the queen's cell, while a few remained in the cell wandering about aimlessly, but making no effort to restore their line. In the meantime, a dense swarm of workers entered the cell, apparently crowding up from different parts of the nest. They climbed on to the body of the queen, seemed to press their heads down into her skin, and in the manner already indicated filled themselves with the fluid contained in her body. Within a few minutes they had removed so much of the fluid that her skin began to form flabby folds. Within half an hour after the piece of earth had fallen we carefully examined the outskirts of the nest in the adjoining rooms of the house. All work had ceased, and when we broke away the masonry we encountered everywhere the
rear-guards of the retreating armies, apparently fleeing to the depths of the earth. All work was discontinued. When we returned to the queen we found she appeared to be recovering from the shock. The movement of her head ceased, and with it the workers who had attacked her began to leave the cell. Very shortly afterwards the normal stream of feeders made their appearance and it appeared to us that supreme efforts were being made to replace as quickly as possible the fluid that had been removed from the queen. This did not take very long. Within an hour at the outside, normal behaviour had been restored. The egg-carriers were again at work and
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the ‘masseurs’ once more appeared on the queen's body, but the ‘guards’ had not reappeared. A few of them were still wandering about among the tiny workers inside the cell; and then we discovered a remarkable fact - as long as the line of ‘guards’ was not restored, the cessation of building-work throughout the nest continued. It was only some hours after the occurrence that the ‘guards’ reappeared and reformed their singular circle round the queen. As soon as this was accomplished, work re-started throughout the nest. I infer from this that the true functions of the line of ‘guards’ are related to the mysterious power which the queen ‘broadcasts’ and which determines the behaviour of every worker and every soldier in the community. I am inclined to think that the angle which the plane of the circle makes with the surface of the earth is also connected with the exercise of the psychological functions of the queen. The fact that their heads point due north along the line of the earth's magnetic plane may also be of some significance. In Australia there is a species of termite known as the Magnetic White Ant which build all their ant-hills with the longer axis pointing north and south. In the Northern Transvaal we have a termite which is similarly influenced by the magnetic force of the earth. I have also found, in the digging of the deep boreholes which they need for their supply of water, that a borehole makes many bends east and west, but there is no bend north or south. Thus an entire borehole was exposed on the northern vertical wall of a mine-shaft sixty-five feet deep.
When the observer has come to regard many of the functions exhibited by different parts of the termite community as identical with those found in the mammalian body, then there is the equivalent of one organ which he would expect to find; that is the important connecting link between the brain and the outlying organs which it controls. I have always sought in the termite community for some or other functional equivalent of the spinal cord in the vertebrates. I am inclined to think that the circle of ‘guards’ is the answer to that quest.
Destruction of the queen invariably takes place when the nest has been so gravely injured that repair seems impossible, even if the queen herself is uninjured. To this, at first sight, there does not seem to be anything analogous in higher organisms. It seems to me, however, to be identical with what takes place when the body had been gravely injured without involving any vital organ. Even where no haemorrhage takes place, the brain, by some kind of nervous reflex, is gradually deprived of life. It becomes bleached and the whole organism dies. In such cases the injured individual is said to have died of ‘shock’. It seems as if some force in the body, instead of striving to keep the brain alive, decides upon its immediate destruction.
There is another puzzling aspect of termite life, one which to my mind can only be explained on the assumption of organic and psychological unity; or
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rather, it is only on accepting this assumption that other instances resembling this aspect are found in nature.
If one examines the perfect winged insects, the king and queen of Eutermes, for instance, it is difficult to believe that those weird monstrosities, the Eutermes soldiers and workers, are descended from them. The law that ‘like produces like’ is so universal and inflexible that these two blind, sexless individuals - differing as widely from each other and from their parents as two different species of animal that are poles apart can possibly differ - have, within my experience, no parallel in nature. There are polymorphic organisms where a species descends through an intermediate variation. But that is not the case with Eutermes. These soldiers and workers have never reproduced their kind. In the direct line of descent there has never been any insect remotely resembling the soldier and worker.
Even more remarkable, to my mind, is the fact that these two-winged insects, with perfectly developed sexual organs and eyes, transmit to the blind and sexless soldier and worker instincts and functions which they themselves never possessed. The king and queen never build; they know nothing of defending themelves by means of an entangling fluid squirted onto an enemy. From where, then, do soldiers and workers derive their complex and unvarying instincts and the functions which accompany them? I have said I do not know of any parallel instance in nature in the case of separate and individual organisms. But I think every observer must be struck by the resemblance that exists between the whole reproductive process in Eutermes, for instance, and what takes place in the bodies of higher mammals. The sexual flight is in every respect analogous to the escape of spermatozoa and ova and the conjunction of a single pair out of the multitudes that are discharged for this purpose. From this single pair - male and female - the communal body is built up, cell by cell. From them originate organs as diverse in form and function as the different termite classes. The separate organs in the animal body, including the more minute organisms, are all engaged in independent purposive labour - ‘instinctive’ functions - which certainly never appear in the direct line of descent of the spermatozoon and ovum. It would appear, therefore, that these two sexual entities are able to transmit somatic and psychological functions which never appear in their own life history to independent organisms. In the case of the originating spermatozoon and ovum, the transmission of these various functions is less puzzling when we come to regard the two organisms as inseparable parts of the body, and not as independent entities. It seems almost like an explanation to say ‘all the functions of the different parts of the animal body are transmitted through the
spermatozoon and ovum, which are parts of the body’. In the same way we could say: ‘The somatic and psychological functions of all the different classes of termite are transmitted through the
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single sexual pair, which are part and parcel of the entire communal body.’
In the ultimate analysis, however, both instances still remain fundamental exceptions to that universal law of organic life: that no organism can transmit to progeny forms, functions and ‘instincts’ which it does not itself possess. It is, therefore, as an outstanding exception to this fundamental law of life that the transmission of forms and functions through the two sexual termites resembles the transmission of various organic forms and functions through the single pair of spermatozoon and ovum.
While we kept the queen under observation the workmen removed a great quantity of ‘building-work’ and ‘fungus-garden’ stuff. There must have been several tons of this material present in the different rooms of the house when the floors were first lifted. Experience had, however, taught the workmen that removal of masonry and gardens - however thoroughly it might be carried out - was never quite effective. The most that it did was to retard the destructive activities of the termites for an indefinite period. If the queen were not discovered and removed, the woodwork within the house was again attacked within a period proportionate to the amount of destruction carried out.
On the third day our queen was removed, and after this the activities and the life of this nest ceased for good. |
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