In the springtime, those who have eyes to see may find a surprise on old walls and dusty roads. Certain tiny faggots, for no apparent reason, set themselves in motion and make their way along by sudden jerks. The lifeless comes to life: the immovable moves. This is indeed amazing. If we look closer, however, we shall solve the riddle.
Enclosed within the moving bundle is a fair-sized Caterpillar, prettily striped with black and white. He is seeking for food, and perhaps for some spot where he can turn into a Moth. He hurries along timidly, dressed in a queer garment of twigs, which completely covers the whole of him except his head and the front part of his body, with its six short legs. At the least alarm he disappears entirely into his case, and does not budge again. This is the secret of the walking bundle of sticks. It is a Faggot Caterpillar, belonging to the group known as the Psyches.
To protect himself from the weather the chilly, bare-skinned Psyche builds himself a portable shelter, a travelling cottage which the owner never leaves until he becomes a Moth. It is, indeed, something better than a hut on wheels, with a thatched roof to it: it is more like a hermit’s frock, made of an unusual kind of material. In the valley of the Danube the peasant wears a goatskin cloak fastened with a belt of rushes. The Psyche wears even rougher raiment than this: he makes himself a suit of clothes out of sticks. And since this would be a regular hair-shirt to a skin so delicate as his, he puts in a thick lining of silk.
This is the secret of the walking bundle of sticks. It is a Faggot belonging to the group known as the Psyches
In April, on the walls of my chief workshop—my stony harmas with its wealth of insect life—I find the Psyche who will supply me with my most detailed information. He is in the torpid state which shows he will soon become a Moth. It is a good opportunity for examining his bundle of sticks, or case.
It is a fairly regular object, shaped like a spindle, and about an inch and a half long. The pieces that compose it are fixed in front and free at the back. They are arranged anyhow, and would form rather a poor shelter against the sun and rain if the hermit had no other protection than this.
At the first glance it appears like thatch; but thatch is not an exact description of it, for grain-stems are rarely found in it. The chief materials are remnants of very small stalks, light, soft, and rich in pith; next in order come bits of grass-leaves, scaly twigs from the cypress-tree, and all sorts of little sticks; and lastly, if the favourite pieces run short, fragments of dry leaves.
In short the Caterpillar, while preferring pithy pieces, will use anything he comes across, provided it be light, very dry, softened by long exposure, and of the right size. All his materials are used just as they are, without any alterations or sawings to make them the proper length. He does not cut the laths that form his roof; he gathers them as he finds them. His work is limited to fixing them at the fore-end.
In order to lend itself to the movements of the travelling Caterpillar, and particularly to enable the head and legs to move freely while a new piece is being fixed in position, the front part of this case or sheath must be made in a special way. Here a casing of sticks is no longer suitable, for their length and stiffness would hamper the workman and even make his work impossible. What is required here is a flexible neck, able to move in all directions. The collection of stakes, therefore, ends suddenly at some distance from the fore-part, and is there replaced by a collar where the silk lining is merely hardened with very tiny particles of wood, which strengthen the material without making it less flexible. This collar, which allows of free movement, is so important that all the Psyches use it, however greatly the rest of their work may differ. All carry, in front of the bundle of sticks, a yielding neck, soft to the touch, formed inside of a web of pure silk and coated outside with a velvety sawdust, which the Caterpillar obtains by crushing up any sort of dry straw.
The same kind of velvet, but dull and faded—apparently through age—finishes the sheath at the back, in the form of a rather long projection, open at the end.
When I remove the outside of the straw casing, shredding it piece by piece, I find a varying number of laths, or tiny sticks. I have counted as many as eighty, and more. Underneath it I find, from one end of the Caterpillar to the other, the same kind of inner sheath that was formerly visible at the front and back only. This inner sheath is composed everywhere of very strong silk, which resists without breaking when pulled by the fingers. It is a smooth tissue, beautifully white inside, drab and wrinkled outside, where it bristles with a crust of woody particles.
Later on we shall see how the Caterpillar makes himself this complicated garment, formed of three layers, one placed upon the other in a definite order. First comes the extremely fine satin which is in direct contact with the skin; next, the mixed stuff dusted with woody matter, which saves the silk and gives strength to the work; and lastly the outer casing of overlapping sticks.
Although all the Psyches wear this threefold garment, the different species make distinct variations in the outer case. There is one kind, for instance, whom I am apt to meet towards the end of June, hurrying across some dusty path near the houses. His case surpasses that of the first species, both in size and in regularity of arrangement. It forms a thick coverlet of many pieces, in which I recognise fragments of hollow stalks, bits of fine straw, and perhaps blades of grass. In front there is never any flounce of dead leaves, a troublesome piece of finery which is pretty frequent, though not always used, in the costume of the first species I described. At the back there is no long projection beyond the outer covering. Save for the indispensable collar at the neck, the whole Caterpillar is cased in sticks. There is not much variety about the thing, but, when all is said, there is a certain beauty in its stern faultlessness.
There is a smaller and more simply dressed Psyche who is very common at the end of winter on the walls, as well as in the bark of gnarled old trees, whether olive-trees or elms, or indeed almost any other. His case, a modest little bundle, is hardly more than two-fifths of an inch in length. A dozen rotten straws, picked up at random and fixed close to one another in a parallel direction, represent, with the silk sheath, his whole outlay on dress.
It would be difficult to clothe oneself more economically.
If I gather a number of little Psyches in April and place them in a wire bell-jar, I can find out more about them. Most of them are in the chrysalis state, waiting to be turned into Moths, but a few are still active and clamber to the top of the wire trellis. There they fix themselves by means of a little silk cushion, and both they and I must wait for weeks before anything further happens.
At the end of June the male Psyche comes out of his case, no longer a Caterpillar, but a Moth. The case, or bundle of sticks, you will remember, had two openings, one in front and one at the back. The front one, which is the more regular and carefully made, is permanently closed by being fastened to the support on which the chrysalis is fixed; so the Moth, when he is hatched, is obliged to come out by the opening at the back. The Caterpillar turns round inside the case before he changes into a Moth.
Though they wear but a simple pearl-grey dress and have insignificant wings, hardly larger than those of a Common Fly, these little male Moths are graceful enough. They have handsome feathery plumes for antennæ, and their wings are edged with delicate fringes. For the appearance of the female Psyche, however, little can be said.
Some days later than the others she comes out of the sheath, and shows herself in all her wretchedness. Call that little fright a Moth! One cannot easily get used to the idea of so miserable a sight: as a Caterpillar she was no worse to look at. There are no wings, none at all; there is no silky fur either. At the tip of her round, tufty body she wears a crown of dirty-white velvet; on each segment, in the middle of the back, is a large, rectangular, dark patch—her sole attempts at ornament. The mother Psyche renounces all the beauty which her name of Moth seems to promise.
As she leaves her chrysalid sheath she lays her eggs within it, thus bequeathing the maternal cottage (or the maternal garment, if you will) to her heirs. As she lays a great many eggs the affair takes some thirty hours. When the laying is finished she closes the door and makes everything safe against invasion. For this purpose some kind of wadding is required. The fond mother makes use of the only ornament which, in her extreme poverty, she possesses. She wedges the door with the coronet of velvet which she carries at the tip of her body.
Finally she does even more than this. She makes a rampart of her body itself. With a convulsive movement she dies on the threshold of her recent home, her cast chrysalid skin, and there her remains dry up. Even after death she stays at her post.
If the outer case be now opened it will be found to contain the chrysalid wrapper, uninjured except for the opening in front, by which the Psyche came out. The male Moth, when obliged to make his way through the narrow pass, would find his wings and his plumes very cumbersome articles. For this reason he makes a start for the door while he is still in the chrysalis state, and comes half-way out. Then, as he bursts his amber-coloured tunic, he finds, right in front of him, an open space where flight is possible.
But the mother Moth, being unprovided with wings and plumes, is not compelled to take any such precautions. Her cylinder-like form is bare, and differs very little from that of the Caterpillar. It allows her to crawl, to slip into the narrow passage, and to come forth without difficulty. So she leaves her cast skin behind her, right at the back of the case, well covered by the thatched roof.
And this is an act of prudence, showing her deep concern for the fate of her eggs. They are, in fact, packed as though in a barrel, in the parchment-like bag formed by the cast skin. The Moth has methodically gone on laying eggs in that receptacle till it is full. Not satisfied with bequeathing her house and her velvet coronet to her offspring, as the last act of her life she leaves them her skin.
Wishing to observe the course of events at my ease I once took one of these chrysalid bags, stuffed with eggs, from its outer casing of sticks, and placed it by itself, beside its case, in a glass tube. In the first week of July I suddenly found myself in possession of a large family. The hatching took place so quickly that the new-born Caterpillars, about forty in number, had already clothed themselves in my absence.
They wore a garment like a sort of Persian head-dress, in dazzling white plush. Or, to be more commonplace, a white cotton night-cap without a tassel. Strange to say, however, instead of wearing their caps on their heads, they wore them standing up from their hind-quarters, almost perpendicularly. They roamed about gaily inside the tube, which was a spacious dwelling for such mites. I was quite determined to find out with what materials and in what manner the first outlines of the cap were woven.
Fortunately the chrysalid bag was far from being empty. I found within the rumpled wrapper a second family as numerous as those already out of the case. Altogether there must have been five or six dozen eggs. I transferred to another place the little Caterpillars who were already dressed, keeping only the naked new-comers in the tube. They had bright red heads; the rest of their bodies was dirty-white; and they measured hardly a twenty-fifth of an inch in length.
I had not long to wait. The next day, little by little, singly or in groups, the little laggards left the chrysalid bag. They came out without breaking that frail object, through the opening in front made by their mother. Not one of them used it as a dress-material, though it had the delicacy and amber colouring of an onion-skin; nor did any of them make use of a certain fine quilting that lines the inside of the bag and forms an exquisitely soft bed for the eggs. One would have thought this downy stuff would make an excellent blanket for the chilly creatures, but not a single one used it. There would not be enough to go round.
They all went straight to the coarse outer casing of sticks, which I had left in contact with the chrysalid skin containing the eggs. The matter was urgent, they evidently felt. Before making your entrance into the world and going a-hunting, you must first be clad. All therefore, with equal fury, attacked the old sheath and hastily dressed themselves in their mother’s old clothes.
Some turned their attention to bits that happened to be opened lengthwise, scraping the soft white inner layer; others, greatly daring, penetrated into the tunnel of a hollow stalk and collected their materials in the dark. The courage of these was rewarded; they secured first-rate materials and wove garments of dazzling white. There were others who bit deeply into the piece they chose, and made themselves a motley covering, in which the snowy whiteness was marred by darker particles.
The tools the little Caterpillars use for this purpose are their mandibles, which are shaped like wide shears and have five strong teeth apiece. The two blades fit into each other, and form an instrument capable of seizing and slicing any fibre, however small. Under the microscope it is seen to be a wonderful specimen of mechanical precision and power. If the Sheep had a similar tool in proportion to her size, she could browse on the stems of trees instead of the grass.
It is very instructive to watch these Psyche-grubs toiling to make themselves a cotton night-cap. There are numbers of things to remark, both in the finish of the work and the skill of the methods they employ. They are so tiny that while I observe them through my magnifying glass I must be careful not to breathe, lest I should overturn them or puff them away. Yet this speck is expert in the art of blanket-making. An orphan, born but a moment ago, it knows how to cut itself a garment out of its mother’s old clothes. Of its methods I will tell you more presently, but first I must say another word with regard to its dead mother.
I have spoken of the downy quilting that covers the inside of the chrysalid bag. It is like a bed of eiderdown, on which the little Caterpillars rest for a while after leaving the egg. Warmly nestling in this soft rug they prepare themselves for their plunge into the outer world of work.
The Eider robs herself of her down to make a luxurious bed for her brood; the mother Rabbit shears from her own body the softest part of her fur to provide a mattress for her new-born family. And the same thing is done by the Psyche.
The mass of soft wadding that makes a warm coverlet for the baby Caterpillar is a material of incomparable delicacy. Through the microscope it can be recognised as the scaly dust, the intensely fine down in which every Moth is clad. To give a snug shelter to the little grubs who will soon be swarming in the case, to provide them with a refuge in which they can play about and gather strength before entering the wide world, the Psyche strips herself of her fur like the mother Rabbit.
This may possibly be done mechanically; it may be the unintentional effect of rubbing repeatedly against the low-roofed walls; but there is nothing to tell us so. Even the humblest mother has her foresight. It is quite likely that the hairy Moth twists about, and goes to and fro in the narrow passage, in order to get rid of her fleece and prepare bedding for her family.
I have read in books that the young Psyches begin life by eating up their mother. I have seen nothing of the sort, and I do not even understand how the idea arose. Indeed, she has given up so much for her family that there is nothing left of her but some thin, dry strips—not enough to provide a meal for so numerous a brood. No, my little Psyches, you do not eat your mother. In vain do I watch you: never, either to clothe or to feed himself, does any one of you lay a tooth upon the remains of the deceased.
I will now describe in greater detail the dressing of the grubs.
The hatching of the eggs takes place in the first fortnight of July. The head and upper part of the little grubs are of a glossy black, the next two segments are brownish, and the rest of the body is a pale amber. They are sharp, lively little creatures, who run about with short, quick steps.
For a time, after they are out of the bag where they are hatched, they remain in the heap of fluff that was stripped from their mother. Here there is more room, and more comfort too, than in the bag whence they came; and while some take a rest, others bustle about and exercise themselves in walking. They are all picking up strength before leaving the outer case.
They do not stay long amid this luxury. Gradually, as they gain vigour, they come out and spread over the surface of the case. Work begins at once, a very urgent work—that of dressing themselves. By and by they will think of food: at present nothing is of any importance but clothes.
Montaigne, when putting on a cloak which his father had worn before him, used to say, “I dress myself in my father.” Well, the young Psyches in the same way dress themselves in their mother. (In the same way, it must be remembered; not in her skin, but in her clothes.) From the outer case of sticks, which I have sometimes described as a house and sometimes as a garment, they scrape the material to make themselves a frock. The stuff they use is the pith of the little stalks, especially of the pieces that are split lengthwise, because the contents are more easily taken from these.
The manner of beginning the garment is worth noting. The tiny creature employs a method as ingenious as any that we could hope to discover. The wadding is collected in pellets of infinitesimal size. How are these little pellets to be fixed and joined together? The manufacturer needs a support, a base; and this support cannot be obtained on the Caterpillar’s own body. The difficulty is overcome very cleverly. The pellets are gathered together, and by degrees fastened to one another with threads of silk—for the Caterpillar, as you know, can spin silk from his own body as the Spider spins her web. In this way a sort of garland is formed, with the pellets or particles swinging in a row from the same rope. When it is long enough this garland is passed round the waist of the little creature, in such a way as to leave its six legs free. Then it ties the ends together with a bit of silk, so that it forms a girdle round the grub’s body.
This girdle is the starting-point and support of the whole work. To lengthen it, and enlarge it into a complete garment, the grub has only to fix to it the scraps of pith which the mandibles never cease tearing from the case. These scraps or pellets are sometimes placed at the top, sometimes at the bottom or side, but they are always fixed at the fore-edge. No device could be better contrived than this garland, first laid out flat and then buckled like a belt round the body.
Once this start is made the weaving goes on well. Gradually the girdle grows into a scarf, a waistcoat, a short jacket, and lastly a sack, and in a few hours it is complete—a conical hood or cloak of magnificent whiteness.
Thanks to his mother’s care the little grub is spared the perils of roaming about in a state of nakedness. If she did not place her family in her old case they might have great difficulty in clothing themselves, for straws and stalks rich in pith are not found everywhere. And yet, unless they died of exposure, it appears that sooner or later they would find some kind of garment, since they seem ready to use any material that comes to hand. I have made many experiments with new-born grubs in a glass tube.
From the stalks of a sort of dandelion they scraped, without the least hesitation, a superb white pith, and made it into a delicious white cloak, much finer than any they would have obtained from the remains of their mother’s clothes. An even better garment was woven from some pith taken from the kitchen-broom. This time the work glittered with little sparks, like specks of crystal or grains of sugar. It was my manufacturers’ masterpiece.
The next material I offered them was a piece of blotting-paper. Here again my grubs did not hesitate: they lustily scraped the surface and made themselves a paper coat. Indeed, they were so much pleased with this that when I gave them their native case they scorned it, preferring the blotting-paper.
To others I gave nothing at all. Not to be baffled, however, they hastened to scrape the cork of the tube and break it into atoms. Out of these they made themselves a frock of cork-grains, as faultless as though they and their ancestors had always made use of this material. The novelty of the stuff, which perhaps no Caterpillar had ever used before, made no difference in the cut of the garment.
Finding them ready to accept any vegetable matter that was dry and light, I next tried them with animal and mineral substances. I cut a strip from the wing of a Great Peacock Moth, and placed two little naked Caterpillars upon it. For a long time they both hesitated. Then one of them resolved to use the strange carpet. Before the day was over he had clothed himself in grey velvet made of the Great Peacock’s scales.
I next took some soft, flaky stones, such as will break at the merest touch into atoms nearly as fine as the dust on a Butterfly’s wing. On a bed of this powdery stuff, which glittered like steel filings, I placed four Caterpillars in need of clothes. One, and one alone, decided to dress himself. His metallic garment, from which the light drew flashes of every colour of the rainbow, was very rich and sumptuous, but mightily heavy and cumbrous. Walking became laborious under that load of metal. Even so must a Byzantine Emperor have walked at ceremonies of State.
In cases of necessity, then, the young Caterpillar does not shrink from acts of sheer madness. So urgent is his need to clothe himself that he will weave mineral matter rather than go naked. Food means less to him than clothes. If I make him fast for a couple of days, and then, having robbed him of his garment, place him on his favourite food, a leaf of very hairy hawkweed, he will make himself a new coat before satisfying his hunger.
This devotion to dress is due, not to any special sensitiveness to cold, but to the young Caterpillar’s foresight. Other Caterpillars take shelter among the leaves, in underground cells, or in the cracked bark of trees, but the Psyche spends his winter exposed to the weather. He therefore prepares himself, from his birth, for the perils of the cold season.
As soon as he is threatened with the rains of autumn he begins to work upon his outer case. It is very rough at first. Straws of uneven length and bits of dry leaves are fastened, with no attempt at order, behind the neck of the sack or undergarment, which must remain flexible so as to allow the Caterpillar to bend freely in every direction. These untidy first logs of the outer case will not interfere with the final regularity of the building: they will be pushed back and driven out as the sack grows longer in front.
After a time the pieces are longer and more carefully chosen, and are all laid on lengthwise. The placing of a straw is done with surprising speed and skill. The Caterpillar turns it round and round between his legs, and then, gripping it in his mandibles, removes a few morsels from one end, and immediately fixes them to the end of the sack. He probably does this in order that the silk may obtain a firmer hold, as a plumber gives a touch of the file to a point that is to be soldered.
Then, by sheer strength of jaw, he lifts and brandishes his straw in the air before laying it on his back. At once the spinneret sets to work and fixes it in place. Without any groping about or correcting, the thing is done. By the time the cold weather arrives the warm case is complete.
But the silky felt of the interior is never thick enough to please the Caterpillar. When spring comes he spends all his spare time in improving his quilt, in making it ever thicker and softer. Even if I take off his outer case he refuses to rebuild it: he persists in adding new layers to the lining, even when there is nothing to be lined. The sack is lamentably flabby; it sags and rumples. He has no protection nor shelter. No matter. The hour for carpentry has passed. The hour has come for upholstering; and he upholsters obstinately, padding a house—or lining a garment—that no longer exists. He will perish miserably, cut up by the Ants, as the result of his too-rigid instinct.
