the flowers, the fruits and down to the very bodies of the subjects studied; for we sometimes find a treble superposition of parasites, as in the Oil-beetles; and we see the maggot itself, the sinister guest at the last feast of all, feed some thirty brigands with its substance.
7
Among the Hymenoptera, which represent the most intellectual class in the world which we are studying, the building-talents of our wonderful Domestic Bee are certainly equal, in other orders of architecture, by those of more than one wild and solitary bee and notably by the Megachile, or Leaf-cutter, a little insect which is not all outside show and which, to house its eggs, manufactures honeypots formed of a multitude of disks and ellipses cut with mathematical precision from the leaves of certain trees. For lack of space, I am unable, to my great regret, to quote the beautiful and pellucid pages which J. H. Fabre, with his usual conscientiousness, devotes to the exhaustive study of this admirable work; nevertheless, since the occasion offers, let us listen to his own words, though it be but for a moment and in regard to a single detail:
'With the oval pieces, the question changes. What model has the Megachile when cutting into fine ellipses the delicate material of the robinia? What ideal pattern guides her scissors? What measure dictates the dimensions? One would like to think of the insect as a living compass, capable of tracing an elliptic curve by a certain natural inflexion of the body, even as our arm traces a circle by swinging from the shoulder. A blind mechanism, the mere outcome of her organization, would in that case be responsible for her geometry. This explanation would tempt me, if the oval pieces of large dimensions were not accompanied by much smaller, but likewise oval pieces, to fill the empty spaces. A compass which changes its radius of itself and alters the degree of curvature according to the exigencies of a plan appears to me an instrument somewhat difficult to believe in. There must be something better than that. The circular pieces of the lid suggest it to us.
'If, by the mere flexion inherent in her structure, the leaf-cutter succeeds in cutting out ovals, how does she manage to cut out rounds? Can we admit the presence of other wheels in the machinery for the new pattern, so different in shape and size? However, the real point of the difficulty does not lie there. Those rounds, for the most part, fit the mouth of the bottle with almost exact precision. When the cell is finished, the bee flies hundreds of yards further to make the lid. She arrives at the leaf from which the disk is to be cut. What picture, what recollection has she of the pot to be covered? Why, none at all: she has never seen it; she works underground, in profound darkness! At the utmost, she can have the indications of touch: not actual indications, of course, for the pot is not there, but past indications, ineffective in a work of precision. And yet the disk must be of a fixed diameter: if it were too large, it would not fit in; if too small, it would close badly, it would smother the egg by sliding down on the honey. How shall it be given its correct dimensions without a pattern? The Bee does not hesitate for a moment. She cuts out her disk with the same rapidity which she would display in detaching any shapeless lobe just useful for closing; and that disk, without further measurement, is of the right size to fit the pot. Let whoso will explain this geometry, which in my opinion is inexplicable, even when we allow for memory begotten of touch and sight.'
Let us add that the author has calculated that, to form the cells of a kindred Megachile, the Silky Megachile, exactly 1,064 of these ellipses and disks would be required; and they must all be collected and shaped in the course of an existence that lasts a few weeks.
8
Who would imagine that the Pentatomida, on the other hand, the poor and evil-smelling bug of the woods, has invented a really extraordinary apparatus wherewith to leave the egg? And first let us state that this egg is a marvellous little box of snowy whiteness, which our author thus describes:
'The microscope discovers a surface engraved with dents similar to those of a thimble and arranged with exquisite symmetry. At the top and bottom of the cylinder is a wide belt of a dead black; on the sides, a large white zone with four big, black spots evenly distributed. The lid, surrounded by snowy cilia and encircled with white at the edge, swells into a black cap with a white knot in the centre. Altogether, a dismal burial urn, with the sudden contrast between the dead black and the fleecy white. The funeral pottery of the ancient Etruscans would have found a magnificent model here.'
The little bug, whose forehead is too soft, covers her head, to raise the lid of the box, with a mitre formed of three triangular rods, which is always at the bottom of the egg at the moment of delivery. Her limbs being sheathed like those of a mummy, she has nothing wherewith to put her tringles in motion except the pulsations produced by the rhythmic flow of blood in her skull and acting after the manner of a piston. The rivets of the lid gradually give way; and, as soon as the insect is free, she lays aside her mechanical helmet.
Another species of bug, the Reduvius personatus, which lives mostly in lumber-rooms, where it lies hidden in the dust, has invented a still more astonishing system of hatching. Here, the lid of the egg is not riveted, as in the case of the Pentatomidæ, but simply glued. At the moment of liberation, the lid rises and we see:
'... a spherical vesicle emerge from the shell and gradually expand, like a soap-bubble blown through a straw. Driven further and further back by the extension of this bladder, the lid falls.
'Then the bomb bursts; in other words, the blister, swollen beyond its capacity of resistance, rips at the top. This envelope, which is an extremely tenuous membrane, generally remains clinging to the edge of the orifice, where it forms a high, white rim. At other times, the explosion loosens it and flings it outside the shell. In those conditions, it is a dainty cup, half spherical, with torn edges, lengthened out below into a delicate, winding stalk.'
Now, how is this miraculous explosion produced? J. H. Fabre assumes that:
'Very slowly, as the little animal takes shape and grows, this bladder-shaped reservoir receives the products of the work of respiration performed under the cover of the outer membrane. Instead of being expelled through the egg-shell, the carbonic acid, the incessant result of the vital oxidization, is accumulated in this sort of gasometer, inflates and distends it and presses upon the lid. When the insect is ripe for hatching, a superadded activity in the respiration completes the inflation, which perhaps has been preparing since the first evolution of the germ. At last, yielding to the increasing pressure of the gaseous bladder, the lid becomes unsealed. The Chick in its shell has its air-chamber; the young Reduvius has its bomb of carbonic acid: it frees itself in the act of breathing.'
One would never weary of dipping eagerly into these inexhaustible treasures. We imagine, for instance, that, from seeing cobwebs so frequently displayed in all manner of places, we possess adequate notions of the genius and methods of our familiar spiders. Far from it: the realities of scientific observation call for an entire volume crammed with revelations of which we had no conception. I will simply name, at random, the symmetrical arches of the Clotho Spider's nest, the astonishing funicular flight of the young of our Garden Spider, the diving-bell of the Water Spider, the live telephone-wire which connects the web with the leg of the Cross Spider hidden in her parlour and informs her whether the vibration of her toils is due to the capture of a prey or a caprice of the wind.
9
It is impossible, therefore, short of having unlimited space at one's disposal, to do more than touch, as it were with the tip of the phrases, upon the miracles of maternal instinct, which, moreover, are confounded with those of the higher manufactures and form the bright centre of the insect's psychology. One would, in the same way, require several chapters to convey a summary idea of the nuptial rites which constitute the quaintest and most fabulous episodes of these new Arabian Nights.
The male of the Spanish-fly, for instance, begins by frenziedly beating his spouse with his abdomen and his feet, after which, with his arms crossed and quivering, he remains long in ecstasy. The newly-wedded Osmiæ clap their mandibles terribly, as though it were a matter rather of devouring each other; on the other hand, the largest of our moths, the Great Peacock, who is the size of a bat, when drunk with love finds his mouth so completely atrophied that it becomes no more than a vague shadow. But