The next day, a third visit. The pear is finished. Its neck, yesterday a yawning sack, is now closed. The egg, therefore, is laid; the work is completed and demands only the finishing touches of general polishing, touches upon which the mother, so intent on geometrical perfection, was doubtless engaged at the time when I disturbed her.
The most delicate part of the business escapes my observation. Roughly speaking, I can see plainly how the egg’s hatching-chamber is obtained: the thick pad surrounding the original crater is thinned and flattened under the pressure of the feet and is lengthened into a sack the mouth of which gradually narrows. Up to this point the work provides its own explanation. But, when we think of the insect’s rigid tools, its broad, toothed fore-arms, whose spasmodic movements remind us of the stiff gestures of an automaton, we are left without any explanation of the exquisite perfection of the cell which is to be the hatching-chamber of the egg.
With this crude equipment, excellently adapted to pickaxe-work though it be, how does the Scarab obtain the natal dwelling, the oval nest so daintily polished and glazed within? Does her foot, a regular saw, fitted with enormous teeth, begin to rival the artist’s brush in delicacy from the moment when it is inserted through the narrow orifice of the sack? Why not? I have said elsewhere, and this is the moment to say it again: the tool does not make the workman. The insect exercises its own particular talents with any kind of tool with which it is supplied. It can saw with a plane or plane with a saw, like the model workman of whom Franklin tells us. The same strong-toothed rake which the Sacred Beetle uses to open up the earth she also employs as a trowel and brush [[82]]wherewith to glaze the stucco of the chamber in which the grub will be born.
In conclusion, one more detail concerning this hatching-chamber. At the extreme end of the neck of the pear, one point is always pretty clearly distinguished: it bristles with stringy fibres, while the rest of the neck is carefully polished. This is the plug with which the mother has closed the narrow opening after carefully depositing the egg; and this plug, as its hairy structure shows, has not been subjected to the pressure exerted over all the rest of the mass, working into it any projecting bits, however small, till not the slightest sign of roughness remains.
Why does the extreme end of the pear receive this special treatment, a most curious exception, when nothing else has eluded the heavy blows of the insect’s legs? The reason is that the hind-end of the egg rests against this plug, which, were it pressed down and driven in, would transmit the pressure to the germ and imperil its safety. So the mother, aware of the risk, stops the hole without ramming down the stopper: the air in the hatching-chamber is thus more easily renewed; and the egg escapes the dangerous activity of the powerful rammer. [[83]]
Chapter vi
THE SACRED BEETLE: THE LARVA
Under the thin ceiling of the burrow, the Sacred Beetle’s egg undergoes the varying influences of the sun, the supreme incubator. Consequently there is not, nor can there be, any fixed date for the quickening of the germ. In very hot, sunny weather, I have obtained a grub five or six days after the egg was laid; with a more moderate temperature, I have had to wait until the twelfth day. June and July are the hatching-months.
As soon as the new-born grub has flung aside its swaddling clothes, it forthwith bites into the walls of its chamber. If starts eating its house, not anyhow, but with unerring wisdom. If it nibbled at the thin side of its cell—and there is nothing to dissuade it, for here as elsewhere the materials are of excellent quality—if its mandibles scraped the extreme end of the nipple, the weakest point, it would make a breach in the protecting wall before it had sufficient putty to repair that breach. This putty is the material which we shall see the larva using later, when accidents of that kind occur from external causes.