Let us add that the author 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 Pentatoma, on the other hand, the poor and evil-smelling Wood-bug, 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 striking burial urn, with the sudden contrast between the coal-black and the fleecy white. The Etruscans would have found a magnificent model here for their funeral pottery.”
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 rods 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, it lays aside its mechanical helmet.
Another species of bug, Reduvius personatus, who lives mostly in lumber-rooms, where she 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 Pentatomae, 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 farther and farther 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? Fabre assumes that:
“Very slowly, as the tiny creature 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.”