The Faber Book of Science (31 page)

A robin's nest with three robin's eggs and one of the cuckoo was found in a low bank at the side of the small orchard on 19th May, 1900. The bird was incubating, and on the afternoon of 27th May the cuckoo hatched out. Unfortunately I did not know how long incubation had been going on before the 19th, but from the fact that the cuckoo was first out, it seems probable that the parasite has this further advantage of coming first from the shell. Long ago I found that this was so in the case of the parasitical troupials of the genus
Molothrus
in South America.

I kept a close watch on the nest for the rest of that afternoon and the whole of the following day (the 28th), during which the young cuckoo was lying in the bottom of the nest, helpless as a piece of jelly with a little life in it, and with just strength enough in his neck to lift his head and open his mouth; and then, after a second or two, the wavering head would drop again. At eight o'clock next morning (29th) I found that one robin had come out of the shell, and one egg had been ejected and was lying a few inches below the nest on the sloping bank. Yet the young cuckoo still appeared a weak, helpless, jelly-like creature, as on
the previous day. But he had increased greatly in size. I believe that in forty-eight hours from the time of hatching he had quite doubled his bulk, and had grown darker, his naked skin being of a bluish-black colour. The robin, thirty or more hours younger, was little more than half his size, and had a pale, pinkish-yellow skin, thinly clothed with a long black down. The cuckoo occupied the middle of the deep, cup-shaped nest, and his broad back, hollow in the middle, formed a sort of false bottom; but there was a small space between the bird's sides and the nest, and in this space or interstice the one unhatched egg that still remained and the young robin were lying.

During this day (29th) I observed that the pressure of the egg and young robin against his sides irritated the cuckoo: he was continually moving, jerking and wriggling his lumpish body this way and that, as if to get away from the contact. At intervals this irritation would reach its culminating point, and a series of mechanical movements would begin, all working blindly but as surely towards the end as if some devilish intelligence animated the seemingly helpless infant parasite.

Of the two objects in the nest the unhatched egg irritated him the most. The young robin was soft, it yielded when pressed, and could be made somehow to fit into the interstice; but the hard, round shell, pressing against him like a pebble, was torture to him, and at intervals became unendurable. Then would come that magical change in him, when he seemed all at once to become possessed of a preternatural power and intelligence, and then the blind struggle down in the nest would begin. And after each struggle – each round it might be called – the cuckoo would fall back again and lie in a state of collapse, as if the mysterious virtue had gone out of him. But in a very short time the pressure on his side would begin again to annoy him, then to torment him, and at last he would be wrought up to a fresh effort. Thus in a space of eight minutes I saw him struggle four separate times, with a period of collapse after each, to get rid of the robin's egg; and each struggle involved a long series of movements on his part. On each of these occasions the egg was pushed or carried up to the wrong or upper side of the nest, with the result that when the bird jerked the egg from him it rolled back into the bottom of the nest. The statement is therefore erroneous that the cuckoo knows at which side to throw the egg out. Of course he
knows
nothing, and, as a fact, he tries to throw the egg up as often as down the slope.

The process in each case was as follows: The pressure of the egg
against the cuckoo's side, as I have said, was a constant irritation; but the irritability varied in degree in different parts of the body. On the under parts it scarcely existed; its seat was chiefly on the upper surface, beginning at the sides and increasing towards the centre, and was greatest in the hollow of the back. When, in moving, the egg got pushed up to the upper edge of his side, he would begin to fidget more and more, and this would cause it to move round, and so to increase the irritation by touching and pressing against other parts. When all the bird's efforts to get away from the object had only made matters worse, he would cease wriggling and squat down lower and lower in the bottom of the nest, and the egg, forced up, would finally roll right into the cavity in his back – the most irritable part of all. Whenever this occurred, a sudden change that was like a fit would seize the bird; he would stiffen, rise in the nest, his flabby muscles made rigid, and stand erect, his back in a horizontal position, the head hanging down, the little naked wings held up over the back. In that position he looked an ugly, lumpish negro mannikin, standing on thinnest dwarf legs, his back bent, and elbows stuck up above the hollow flat back.

Once up on his small stiffened legs he would move backwards, firmly grasping the hairs and hair-like fibres of the nest-lining, and never swerving, until the rim of the cup-like structure was reached; and then standing, with feet sometimes below and in some cases on the rim, he would jerk his body, throwing the egg off or causing it to roll off. After that he would fall back into the nest and lie quite exhausted for some time, his jelly-like body rising and falling with his breathing.

These changes in the bird strongly reminded me of a person with an epileptic fit, as I had been accustomed to see it on the pampas, where, among the gauchos, epilepsy is one of the commonest maladies: the sudden rigidity of muscle in some weak, sickly, flabby-looking person, the powerful grip of the hand, the strength in struggling, exceeding that of a man in perfect health, and finally, when this state is over, the weakness of complete exhaustion.

I witnessed several struggles with the egg, but at last, in spite of my watchfulness, I did not see it ejected. On returning after a very short absence I found the egg had been thrown out and had rolled down the bank, a distance of fourteen inches from the nest.

The young cuckoo appeared to rest more quietly in the nest now, but after a couple of hours the old fidgeting began again, and increased, until he was in the same restless state as before. The rapid
growth of the birds made the position more and more miserable for the cuckoo, since the robin, thrust against the side of the nest, would throw his head and neck across the cuckoo's back, and he could not endure being touched there. And now a fresh succession of struggles began, the whole process being just the same as when the egg was struggled with. But it was not so easy with the young bird, not because of its greater weight, but because it did not roll like the egg and settle in the middle of the back; it would fall partly on to the cuckoo's back and then slip off into the nest again. But success came at last, after many failures. The robin was lying partly across the cuckoo's neck, when, in moving its head, its little curved beak came down and rested on the very centre of that irritable hollow in the back of its foster-brother. Instantly the cuckoo pressed down into the nest, shrinking away as if hot needles had pricked him, as far as possible from the side where the robin was lying against him, and this movement of course brought the robin more and more over him, until he was thrown right upon the cuckoo's back.

Instantly the rigid fit came on, and up rose the cuckoo as if the robin weighed no more than a feather on him; and away backwards he went, right up the nest, without a pause, and standing actually on the rim, jerked his body, causing the robin to fall off, clean away from the nest. It fell, in fact, on to a large dock leaf five inches below the rim of the nest, and rested there.

After getting rid of his burden the cuckoo continued in the same position, perfectly rigid, for a space of five or six seconds, during which it again and again violently jerked its body, as if it had the feeling of the burden on it still. Then, the fit over, it fell back, exhausted as usual.

The end of the little history – the fate of the ejected nestling and the attitude of the parent robins – remains to be told. When the young cuckoo throws out the nestlings from nests in trees, hedges, bushes, and reeds, the victims, as a rule, fall some distance to the ground, or in the water, and are no more seen by the old birds. Here the young robin, when ejected, fell a distance of but five or six inches, and rested on a broad, bright green leaf, where it was an exceedingly conspicuous object; and when the mother robin was on the nest – and at this stage she was on it a greater part of the time – warming that black-skinned, toad-like spurious babe of hers, her bright, intelligent eyes were looking full at the other one, just beneath her, which she had grown in
her body and had hatched with her warmth, and was her very own. I watched her for hours; watched her when warming the cuckoo, when she left the nest and when she returned with food, and warmed it again, and never once did she pay the least attention to the outcast lying there so close to her. There, on its green leaf, it remained, growing colder by degrees, hour by hour, motionless, except when it lifted its head as if to receive food, then dropped it again, and when, at intervals, it twitched its body as if trying to move. During the evening even these slight motions ceased, though that feeblest flame of life was not yet extinguished; but in the morning it was dead and cold and stiff; and just above it, her bright eyes on it, the mother robin sat on the nest as before, warming her cuckoo.

How amazing and almost incredible it seems that a being such as a robin, intelligent above most birds as we are apt to think, should prove in this instance to be a mere automaton! The case would, I think, have been different if the ejected one had made a sound, since there is nothing which more excites the parent bird, or which is more instantly responded to, than the cry of hunger or distress of the young. But at this early stage the nestling is voiceless – another point in favour of the parasite. The sight of its young, we see, slowly and dumbly dying, touches no chord in the parent: there is, in fact, no recognition; once out of the nest it is no more than a coloured leaf, or a bird-shaped pebble, or fragment of clay.

Alfred
Russel
Wallace’s
revival
of
the
theory
that
this
earth
is
at
the
centre
of
the
stellar
universe,
and
is
the
only
habitable
globe,
has
aroused
great
interest
in
the
world.
– Literary Digest

For
ourselves
we
do
thoroughly
believe
that
man,
as
he
lives
just
here
on
this
tiny
earth,
is
in
essence
and
possibilities
the
most
sublime
existence
in
all
the
range
of
non-divine
being
–
the
chief
love
and
delight
of
God.
–
Chicago ‘Interior’
(Presb.)

I seem to be the only scientist and theologian still remaining to be heard from on this important matter of whether the world was made for man or not. I feel that it is time for me to speak.

I stand almost with the others. They believe the world was made for man, I believe it likely that it was made for man; they think there is proof, astronomical mainly, that it was made for man, I think there is evidence only, not proof, that it was made for him. It is too early, yet, to arrange the verdict, the returns are not all in. When they are all in, I think that they will show that the world was made for man; but we must not hurry, we must patiently wait till they are all in.

Now as far as we have got, astronomy is on our side. Mr Wallace has clearly shown this. He has clearly shown two things: that the world was made for man, and that the universe was made for the world – to stiddy it, you know. The astonomy part is settled, and cannot be challenged.

We come to the geological part. This is the one where the evidence is not all in, yet. It is coming in, hourly, daily, coming in all the time, but naturally it comes with geological carefulness and deliberation, and we must not be impatient, we must not get excited, we must be calm, and wait. To lose our tranquillity will not hurry geology; nothing hurries geology.

It takes a long time to prepare a world for man, such a thing is not done in a day. Some of the great scientists, carefully ciphering the evidences furnished by geology, have arrived at the conviction that our world is prodigiously old, and they may be right, but Lord Kelvin is not of their opinion. He takes a cautious, conservative view, in order to be on the safe side, and feels sure it is not so old as they think. As Lord Kelvin is the highest authority in science now living, I think we must yield to him and accept his view. He does not concede that the world is more than a hundred million years old. He believes it is that old, but not older. Lyell believed that our race was introduced into the world 31,000 years ago. Herbert Spencer makes it 32,000. Lord Kelvin agrees with Spencer.

Very well. According to these figures it took 99,968,000 years to prepare the world for man, impatient as the Creator doubtless was to see him and admire him. But a large enterprise like this has to be conducted warily, painstakingly, logically. It was foreseen that man would have to have the oyster. Therefore the first preparation was made for the oyster. Very well, you cannot make an oyster out of whole cloth, you must make the oyster’s ancestor first. This is not done in a day. You must make a vast variety of invertebrates, to start with – belemnites, trilobites, jebusites, amalekites, and that sort of fry, and put them to soak in a primary sea, and wait and see what will happen. Some will be a disappointment – the belemnites, the ammonites and such; they will be failures, they will die out and become extinct, in the course of the 19,000,000 years covered by the experiment, but all is not lost, for the amalekites will fetch the home-stake, they will develop gradually into encrinites, and stalactites, and blatherskites, and one thing and another as the mighty ages creep on and the Archaean and
the Cambrian Periods pile their lofty crags in the primordial seas, and at last the first grand stage in the preparation of the world for man stands completed, the Oyster is done. An oyster has hardly any more reasoning power than a scientist has; and so it is reasonably certain that this one jumped to the conclusion that the nineteen-million years was a preparation for
him
; but that would be just like an oyster, which is the most conceited animal there is, except man. And anyway, this one could not know, at that early date, that he was only an incident in a scheme, and that there was some more to the scheme, yet.

The oyster being achieved, the next thing to be arranged for in the preparation of the world for man, was fish. Fish, and coal – to fry it with. So the Old Silurian seas were opened up to breed the fish in, and at the same time the great work of building Old Red Sandstone mountains 80,000 feet high to cold-storage their fossils in was begun. This latter was quite indispensable, for there would be no end of failures again, no end of extinctions – millions of them – and it would be cheaper and less trouble to can them in the rocks than keep tally of them in a book. One does not build the coal beds and 80,000 feet of perpendicular Old Red Sandstone in a brief time – no, it took twenty million years. In the first place, a coal bed is a slow and troublesome and tiresome thing to construct. You have to grow prodigious forests of tree-ferns and reeds and calamites and such things in a marshy region; then you have to sink them under out of sight and let them rot; then you have to turn the streams on them, so as to bury them under several feet of sediment, and the sediment must have time to harden and turn to rock; next you must grow another forest on top, then sink it and put on another layer of sediment and harden it; then more forest and more rock, layer upon layer, three miles deep – ah, indeed it is a sickening slow job to build a coal-measure and do it right!

So the millions of years drag on; and meantime the fish-culture is lazying along and frazzling out in a way to make a person tired. You have developed ten thousand kinds of fishes from the oyster; and come to look, you have raised nothing but fossils, nothing but extinctions. There is nothing left alive and progressive but a ganoid or two and perhaps half a dozen asteroids. Even the cat wouldn’t eat such.

Still, it is no great matter; there is plenty of time, yet, and they will develop into something tasty before man is ready for them. Even a ganoid can be depended on for that, when he is not going to be called on for sixty million years.

The Palaeozoic time-limit having now been reached, it was necessary to begin the next stage in the preparation of the world for man, by opening up the Mesozoic Age and instituting some reptiles. For man would need reptiles. Not to eat, but to develop himself from. This being the most important detail of the scheme, a spacious liberality of time was set apart for it – thirty million years. What wonders followed! From the remaining ganoids and asteroids and alkaloids were developed by slow and steady and pains-taking culture those stupendous saurians that used to prowl about the steamy world in those remote ages, with their snaky heads reared forty feet in the air and sixty feet of body and tail racing and thrashing after. All gone, now, alas – all extinct, except the little handful of Arkansawrians left stranded and lonely with us here upon this far-flung verge and fringe of time.

Yes, it took thirty million years and twenty million reptiles to get one that would stick long enough to develop into something else and let the scheme proceed to the next step.

Then the Pterodactyl burst upon the world in all his impressive solemnity and grandeur, and all Nature recognized that the Cainozoic threshold was crossed and a new Period open for business, a new stage begun in the preparation of the globe for man. It may be that the Pterodactyl thought the thirty million years had been intended as a preparation for himself, for there was nothing too foolish for a Pterodactyl to imagine, but he was in error, the preparation was for man. Without doubt the Pterodactyl attracted great attention, for even the least observant could see that there was the making of a bird in him. And so it turned out. Also the makings of a mammal, in time. One thing we have to say to his credit, that in the matter of picturesqueness he was the triumph of his Period; he wore wings and had teeth, and was a starchy and wonderful mixture altogether, a kind of long-distance premonitory symptom of Kipling’s marine:

From this time onward for nearly another thirty million years the preparation moved briskly. From the Pterodactyl was developed the bird; from the bird the kangaroo, from the kangaroo the other marsupials; from these the mastodon, the megatherium, the giant sloth, the Irish elk, and all that crowd that you make useful and
instructive fossils out of – then came the first great Ice Sheet, and they all retreated before it and crossed over the bridge at Behring’s strait and wandered around over Europe and Asia and died. All except a few, to carry on the preparation with. Six Glacial Periods with two million years between Periods chased these poor orphans up and down and about the earth, from weather to weather – from tropic swelter at the poles to Arctic frost at the equator and back again and to and fro, they never knowing what kind of weather was going to turn up next; and if ever they settled down anywhere the whole continent suddenly sank under them without the least notice and they had to trade places with the fishes and scramble off to where the seas had been, and scarcely a dry rag on them; and when there was nothing else doing a volcano would let go and fire them out from wherever they had located. They led this unsettled and irritating life for twenty-five million years, half the time afloat, half the time aground, and always wondering what it was all for, they never suspecting, of course, that it was a preparation for man and had to be done just so or it wouldn’t be any proper and harmonious place for him when he arrived.

And at last came the monkey, and anybody could see that man wasn’t far off, now. And in truth that was so. The monkey went on developing for close upon 5,000,000 years, and then turned into a man – to all appearances.

Such is the history of it. Man has been here 32,000 years. That it took a hundred million years to prepare the world for him is proof that that is what it was done for. I suppose it is. I dunno. If the Eiffel tower were now representing the world’s age, the skin of paint on the pinnacle-knob at its summit would represent man’s share of that age; and anybody would perceive that that skin was what the tower was built for. I reckon they would, I dunno.