5. Luminosity in the Animal Kingdom
THE ordinary use of light by the glow-worm and firefly is well known to dwellers in South Africa. Here in the Transvaal the fireflies at times make an amazing show. On the slopes of the Highveld they appear at times in such numbers that the river-beds stretch into the night like streams of light as far as the eye can see. I must confess at once that I do not know for certain what is the motive of this signal. In spite of long and careful observation, I never succeeded in actually seeing the result, if there was one, of the signal. It almost seems as though the insect purposely hides her motive when she becomes aware of being observed. In this respect the firefly reminds me of the pollination of one of our grasses, Aristida. If you ever wish to undertake heartbreaking and hopeless investigation, I advise you to try to be a witness to this pollination. I remember how I watched one whole day until after midnight at the side of the unpollinated plant. At night acetylene mine lamps were lit which cast a circle of light as clear as day for nearly a hundred yards round the plant. And then at last, when weary and exhausted I went to sleep for a couple of hours, I woke to find that the miracle had taken place while I slept -- for the pollination takes place when you least expect it: an hour or two before daybreak. In the same way I spent many sleepless nights watching the firefly and never convinced myself what the motive of the signal could be. I think it is a sexual signal. If there is a doubt, it arises through the fact that the sexes are not dependent only on the light for their sexual life. There are other land creatures which also become luminous periodically. The most wonderful, certainly the most entrancing, is the large green centipede which is found in tropical parts of Africa. Perhaps this gigantic centipede causes more fear and horror in people unused to handling such creatures than any other. For some reason -- which I do not know -- this monster sometimes becomes luminous. It is a rare occurrence. I have only seen it twice. The spectacle is one which the lucky beholder will never forget. If you come across the creature in the dark, while it is luminous, your first conclusion is that it must be a necklace of precious jewels. What would not a lovely lady give for a necklace like that! It is about twelve inches long -- both mine were females -- and while the luminosity lasts the creature, usually so nimble and quick, appears to be in a state of cataleptic paralysis. It appears as though all its energy is being used for the generation of the brilliant light. So bright is the illumination that fine print can easily be read in a dark room at a distance of two feet. What causes the light? I have no idea. A friend of mine, a chemist, examined all the organs of one of these luminous centipedes and he could find no trace of any known light-giving element; under the low power of the microscope the light appeared to come from two luminous patches near the ends of each segment of the body. The light is in continuous movement, an irregular glowing and paling which expands and contracts in concentric circles coming from an intense centre of white light. The circles of light are independent of each other. Coincident with the change in intensity there is a constant and amazing change in the colours of the circles of light. Passing outwards from the white centre, the colours appear in the following order: light yellow, light green, emerald green, dark green, blue, dark blue, red, purple, violet. The source of the light lies within the body of the insect and is irradiated through the skin. In the glow-worm the source of the light appears to be outside the skin. You will see that there is a great unexplored field of work in connection with the signals of animals. That is why I have told you about luminosity to complete our list of signals. I like writing about the firefly, too, for the very reason that this little insect is still wrapped in intriguing mystery.
What is the motive of the light? What is the light? I must confess ignorance. I can tell you very well what it is not, but the opposite side of the balance sheet will remain blank. This happens frequently when we study animals which make use of well-known forces of nature.
A group of termites in which can be seen workers, soldiers and nymphs
|
The South African jelly-fish, for example, has as a means of defence a charge of electricity, with which he shocks you if he touches you under the water. Now the whole of the body of the jelly-fish is filled with water, which is a perfect conductor without insulation; it is surrounded by sea-water which is a far better conductor than the human body. In such conditions it appears impossible for the creature to generate a charge of electricity and still more impossible to direct it through human skin. The creature simply cannot do it -- yet it does!
While we are talking of fireflies and glow-worms, I want to question one theory -- very diffidently. The famous Fabre died under the firm impression that he had discovered the secret of the light. On the skin of the insect we find a white powder, which looks very much like frost. On to this the insect projects two streams of air; the light disappears in the absence of oxygen. Fabre therefore concluded that the phenomenon was nothing else than oxidation. He had no further doubts and his statement has been repeated by many writers. I would like to say this: If it is oxidation, then it is a form of oxidation which is found nowhere else in nature, which the cleverest chemist cannot imitate, and which would necessitate a complete revision of all our beliefs about the properties of oxygen.
Oxidation always generates heat. If it takes place very slowly -- like for instance the rusting of a metal -- then the heat is generated so slowly that it is not noticed -- but still there is heat. If oxidation takes place rapidly, the generation of heat becomes explosive. When oxidation takes place quickly enough to cause light, there must be a previous and continuous generation of heat. Oxidation without this phenomenon is just as impossible as fire without light or heat. If oxygen is necessary for the firefly's light, that does not prove that the light is due to oxidation, as Fabre claimed. Take several fireflies and test them with a sensitive thermometer; you will find there is no rise in temperature due to the light. One could prove that to produce a light equal in strength to that of the firefly for one hour, the bodies of more than eighteen hundred fireflies would have to be burnt. I think Fabre's theory was wrong.
Another word about light. Some years ago a Japanese naturalist discovered that the firefly emits rays which affect a photographic plate through the black covering. These rays must be those which are imperceptible to the human eye. I have been unable to test this myself, or to discover whether our fireflies also emit these rays.
6. The Composite Animal
THE division 'group soul' in our classification of psychological movements is one which the human mind finds most difficult to understand. The further we depart from our own psychological characteristics, the more mystified and puzzled do we become, and the true group soul is the opposite extreme to the psyche, i.e. of the primate, which consists of uninherited, individual causal memory of the environment. The most perfect example of the group soul can be observed in our own bodies. The human body is composed of a number of organs, each connected by a visible or invisible thread to the central point, the brain. Each organ is in constant activity and has a separate purpose -- at least the purpose appears to be separate and independent; but on closer observation we find that all the organs are really working for a communal purpose. The influence dominating all the organs comes from one central point. In no single organ can we find a real independent purpose. After the composite physical body of a highly developed animal like man, there is no better example of the functioning of a group soul than the termitary.
I am now entering a province which will tax your credulity to the utmost, so I will go slowly step by step, making certain of one before we take the next. I promise that I will make no statement which cannot be proved experimentally and, when the facts appear too wonderful and incredible, I will tell you the experiments in order to enable you to repeat them and perhaps even improve on them.
In everyone who carefully observes the termite, the question is bound to arise, 'Why do they continue working? What is the mainspring of this restless activity?' Restless it is indeed. Do you know that of equally developed creatures the termite is the only one which apparently never rests or sleeps? However carefully you observe it, you will never surprise the termite at rest or asleep.
What is the aim of this ceaseless toil and struggle? In other individual animals nature has planted great irresistible urges, the sexual and parental urge, the urge to defence, the urge for food and drink. These urges constitute the psyche of the individual and dominate its movements. In the individual termite there are none of these urges to act as a driving force.
The answers to these questions really constitute the definition of a true group soul. In order to be perfectly clear I will give my line of investigation in the form of theses.
- All the movements of the termite are controlled from without the individual. The termite possesses no vestige of free will, or power of choice. The only quality it possesses is automobility -- power of moving itself. It puts itself into motion, but when this motion will take place or what will be done with it, is decided, controlled from without. Circumstances may render the termite's work useless and vain; in cases where the simplest insect individually controlled would shrink from its destiny the termite must carry on. It must follow the path along which the unseen arbiter of its fate urges it to go.
- The whole behaviour of the termite is determined from without by an influence -- we may call it a thread by which he is firmly tied to the queen's cell. This invisible influence streams from the organism of the queen alone. It is a power beyond our senses; it can penetrate all material barriers, even such as thin steel or iron plates.
- Distance lessens the influence: it has power only between fixed limits.
- The somatic death of the queen destroys the influence immediately. Injuries and wounds sustained by the queen weaken the influence in proportion to the size of the injury.
- The termitary is a separate composite animal at a certain stage of development, and lack of automobility alone differentiates it from other such animals.
- The termite has descended from an ordinary flying solitary insect. The development of specialized groups and their amalgamation is a late occurrence in the race-history of the termite.
- The termitary is an example of the method in which composite and highly developed animals like the mammals came into being.
- The body of a mammal with its many vital organs can be looked upon as a community with specialized individuals grouped into organs, the whole community forming the composite animal. The higher the development of the animal, the higher the specialization of the groups.
- This phenomenon of specialized groups of individuals being developed into different organs and becoming a composite animal can actually be observed today in nature.
The group soul, which is surely the most amazing psychological phenomenon in the natural world and gives the strongest proof that it may be possible for a psychological influence to have effect on an organism at a distance, is the result of this communal life. It is important therefore that we should observe the composite organism and try to understand it. The particular kind of termite on which I based these observations is one of the most common, in South Africa, and everyone will be able to study it.
If you make a breach in any termite's nest on the veld, it will in all likelihood be the nest of the kind of which I am speaking. In the breach you will see two kinds of insects, differing so greatly from each other that if you know nothing of termites it will take a great deal to convince you that they had the same mother and father. One is an ordinary whitish insect with strong jaws, and two black spots which appear to be eyes. The other, under a magnifying glass, looks like a nightmarish monster. It is reddish yellow in colour but when many are massed together the red colour becomes dominant. The body ends in a massive triangular head tapering to a long black hornlike needle or syringe. Below the neck there are four almost rudimentary legs in addition to the other ordinary functioning legs. This needle or syringe is in direct communication with a large reservoir of fluid. In your wildest imagination you could not create a creature more totally cut off from the outside world. Except its two antennae, there is no trace or sign of any organ of sense. How and what the creature eats is a riddle. The only possible food would have to be a thin fluid. The ordinary food which is carried into the nest must have undergone a great change in the bodies of the other termites before this horned beast could make use of it. It is not necessary for our purpose to theorize about all the probable functions of these insects. With a fairly powerful magnifying glass you will see at once that the behaviour of these two kinds of termites in the breach is not identical. The syringe-bearers throng in increasing numbers and, with their syringes pointing outwards, quickly form a ring round the opening. If you tease one of these termites with a stiff bristle, a kind of conclusive movement passes over it, while it makes a stabbing movement with its weapon in all directions. Eventually a crystal clear drop of sticky fluid appears at the end of the syringe. This fluid contains a certain amount of stinging acid. There can be no doubt that these syringe-bearers are there to defend the nest against the enemy, relying on their terrifying appearance as well as their weapons. Apart from this they do nothing. Protected by this cordon of defenders, the other termites begin working busily. They begin to mend the breach, or to heal the wound. From the depths of the termitary, each appears carrying a tiny grain of sand or earth in its jaws. With the help of similar rudimentary legs as those described in the syringe-bearers, the grain is turned about rapidly. Under the microscope you will find that the object of this is to coat it with a similar sticky fluid. It is then fastened to some section of the wound. It cannot fall. If you touch the newly built section, your fingers become sticky, as if you had touched some syrup. This fluid has the property of evaporating very rapidly, and as soon as evaporation has taken place the stickiness disappears.
One of my theses was that the termitary is a separate and perfect animal, which lacks only the power of moving from place to place. I will give you my proofs of this little by little, and the explanation will make clear at the same time the beginning and development of the group soul. Up to now you have learnt what happens in a wounded termitary. Let us turn our attention for a moment to a far more developed composite organism before we return to the termitary.
 
Material from termitaries
|
I take for granted that you have a general idea of the construction of your own body and how that machine works. You know that your body consists of millions of cells, through which there is constantly flowing a fluid which we term blood. The fluid consists chiefly of two separate kinds of organism, red and white corpuscles, each of which is a living cell having a life or soul of its own as well as a group soul. These corpuscles build up the body, mend wounds and attack germs. Metchnikoff's conclusions in this connection, although doubtful in certain respects, are nevertheless true in their general lines.
The attacking microbes are themselves attacked and devoured in the wound or in the natural orifices, or, if they succeed in entering, the fight is carried on in the cells and passages. Every wound swarms with defending white corpuscles. If a germ of disease enters the system there is an even leucocytosis or increase of white corpuscles. Both growth and healing always take place from within outwards. Covering the vital organs we have the epidermis or skin, a tough impenetrable covering which shuts out light and air. The corpuscles of the blood are afraid of air and light. The growth of the body is more wonderful and mysterious than we realize. We are far too prone to consider every ordinary natural phenomenon as a kind of axiom which needs no explanation, like, for instance, the fall of an apple to the ground. Just consider for a moment the growth of the body, with particular reference to the skin. Growth always takes place from within outward. But we do not find a piece of skin being removed, a piece of an organ being built, and then a new skin being grown over the wound. The growth takes place under the skin. You would be justified in expecting either that the skin should stretch or that a new piece of the body should be grown on top of the old skin and then a new skin over that, so that if you cut into the body you would find layers of old skin. Neither of these things happen. Well, you say, of course the skin grows in the same way that the internal parts grow. It is easy to say this, but we cannot find any proof of it. We know that all growth is caused by the corpuscles in the blood-stream. But we know that these corpuscles never come in contact with the dermis or outer skin. How this outer skin grows at the same rate as the other organs we cannot explain. You know, too, that your body consists of several large organs, each of which functions independently. According to our classification each of these is a separate animal with a separate psyche. Then you have another organ which is the home of the group soul -- the brain -- the centre of the community which is the body.
You have learnt by this time that soul and life are identical. Every definition for soul will be equally as good for life, and vice versa. I have never observed any occurrence which tended to prove that soul and life were two separate entities. They are one and the same. The only difference lies in the two names, which have been given to the same thing.
A small injury to the central point, the brain, is sufficient to cause immediate death of the whole body. The growth and life of the body can continue only with the help of the red and white corpuscles of the blood. Food is taken through a foramen, the mouth, and, after being changed or digested by certain organs, is absorbed by the corpuscles. Ninety per cent of this food is carried to different parts of the body and used as cells to make new muscle, sinews and bone. A portion of the food consists of unassimilable material, but this must be absorbed by the corpuscles with that which is assimilable, because it forms part of the assimilable material. Within their own bodies, the corpuscles separate the assimilable and unassimilable, and the waste is eventually cast from the body as excreta.
I have just said that a small injury of the brain is sufficient to cause the death of the body. Let us study some of the peculiar and mysterious aspects of the condition we call death.
We know that a living person can remain in water for ten days without any part of his skin dissolving. The channel swimmers stay in the sea for twenty-four hours and their skin is quite undamaged by this immersion. Water cannot wash away any part of the living skin, in fact the skin of a living man is as insoluble in water as india-rubber. The whole body of a living person is full of elasticity and possesses a great power of resistance to blows of blunt objects. Remember these two characteristics:
- Insolubility of the skin.
- The general touch-resisting powers and the elasticity of the whole living body.
The change which takes place in these two respects after death is astounding. Have you ever seen a drowned man who has been in the water for some hours? You will remember the gruesome change. What has caused this? As soon as life ends, the epidermis becomes more and more soluble in water; and the body immediately begins to lose its elasticity and power of resistance, until at last even a child could poke a blunt object right through the body. To put it baldly, every part becomes spongy and falls into decay. The physiologist expresses all this differently, generally in long Latin or Greek words, but the meaning remains unchanged. He says: As soon as death has taken place, the more complex components break up into simpler ones. Microbes appear, to hasten the process. This does not help us to understand things more clearly, for the following reasons:
The body consists largely of dead matter. All the cell walls and the outer skin are made up of ordinary dead matter -- or chemical substances. What do the corpuscles do to prevent the solubility of the skin and to protect the elasticity and structure of the body? No one knows. The presence or absence of the corpuscles makes this vast difference. You have heard doubtless of a certain mysterious phenomenon in chemistry -- how the mere presence of one element can change the chemical make-up of another element. The same kind of function is played by the living corpuscles in the blood-stream. This secret, inexplicable influence, which their mere presence has on the chemical and physical character of dead matter, is the mystery of life. In the simplest living cell, such as the blood corpuscle, we find something which not only enables it to move, but which also prevents the breaking up of the cell material. Antagonistic forces of nature are always present ready to break up the cell. Here we find the beginning of the struggle for life -- the attempt to frustrate the inimical forces of nature. The first purpose or urge is a tug of war between the life or soul and matter. This influence at a distance of certain substances specially secreted by the body for this purpose is a well-known biological phenomenon.
The human body possesses a number of ductless glands, whose function it is to produce certain secretions. The mere presence of these secretions exercises a great influence on the whole physical make-up. The adrenal glands for instance produce a substance, adrenaline, which is responsible, amongst other things, for the blood pressure. The gland itself is completely isolated from the rest of the body and yet has this influence at a distance.
After this lesson in physiology and biology, we can now return to study the termitary in the light of our new knowledge. You may wonder how I can call a heap of dead earth like the termitary a living animal. Do not forget that the termitary is no more dead than the dead matter of cell walls which constitutes nine-tenths of your own body. We are ourselves no more than dead termitaries, through which circulates a living substance.
If you destroy a termitary you find firstly a tough resistant skin all around it. Under this skin you find that the whole termitary consists of cells through which a living stream constantly circulates. As you go deeper you find large passages and eventually a hollow, partly or entirely filled with more cells, which are of a different consistency from those of the actual heap. These cells no longer consist of earth and are covered within and without with a kind of mould. This mould is often used in South Africa to make yeast. If you go deep enough and observe carefully you will find at the very bottom a passage which goes right into the earth. If the termitary is an old one and placed on top of a dry kopje or hill, this passage descends to an incredible depth. It is the canal by which the termites get their water supply. They continue the shaft until at last they reach permanently moist ground. On the farm Rietfontein in Waterberg I had the opportunity of following such a passage to a depth of more than 57 feet through earth as hard as rock in the side of a mine pit. The termites need a great deal of moisture. More than ninety per cent of their tiny bodies consist of water, and the whole termitary is always damp and filled with water vapour. Where they managed to get all this moisture in our dry districts would have remained a dark secret if someone had not discovered the existence of the deep vertical aqueduct.
Next: 7. Somatic Death
Table of Contents
Back to the Small Farms Library
