About a week or ten days after the laying of the egg, the grub is hatched, and without delay begins to eat its house. It is a grub of remarkable wisdom, for it always starts its meal with the thickest part of the walls, and so avoids making a hole through which it might fall out of the pear altogether. It soon becomes fat; and indeed it is an ungainly creature at best, with an enormous hump on its back, and a skin so transparent that if you hold it up to the light you can see its internal organs. If the early Egyptian had chanced upon this plump white grub he would never have suspected it to contain, in an undeveloped state, the sober beauty of the Scarab!
When first it sheds its skin the insect that appears is not a full-grown Scarab, though all the Scarab’s features can be recognised. There are few insects so beautiful as this delicate creature with its wing-cases living in front of it like a wide pleated scarf and its fore-legs [[22]]folded under its head. Half transparent and as yellow as honey, it looks as though it were carved from a block of amber. For four weeks it remains in this state, and then it too casts its skin.
Its colouring now is red-and-white,—so many times does the Sacred Beetle change its garments before it finally appears black as ebony! As it grows blacker it also grows harder, till it is covered with horny armour and is a full-grown Beetle.
All this time he is underground, in the pear-shaped nest. Great is his longing to burst the shell of his prison and come into the sunshine. Whether he succeeds in doing so depends on circumstances.
It is generally August when he is ready for release, and August as a rule is the driest and hottest month of the year. If therefore no rain falls to soften the earth, the cell to be burst and the wall to be broken defy the strength of the insect, which is helpless against all that hardness. The soft material of the nest has become an impassable rampart; it has turned into a sort of brick, baked in the kiln of summer.
I have, of course, made experiments on insects that are ready to be released. I lay the hard, dry shells in a box where they remain dry; and sooner or later I hear a sharp, grating sound inside each cell. It is the prisoner scraping the wall with the rakes on his forehead [[23]]and his fore-feet. Two or three days pass, and no progress seems to have been made.
I try to help a couple of them by opening a loophole with my knife; but these favoured ones make no more progress than the others.
In less than a fortnight silence reigns in all the shells. The prisoners, worn out with their efforts, have all died.
Then I take some other shells, as hard as the first, wrap them in a wet rag, and put them in a corked flask. When the moisture has soaked through them I rid them of the wrapper, but keep them in the flask. This time the experiment is a complete success. Softened by the wet the shells are burst by the prisoner, who props himself boldly on his legs, using his back as a lever, or else scrapes away at one point till the walls crumble to pieces. In every case the Beetle is released.
In natural conditions, when the shells remain underground, the same thing occurs. When the soil is burnt by the August sun it is impossible for the insect to wear away his prison, which is hard as a brick. But when a shower comes the shell recovers the softness of its early days: the insect struggles with his legs and pushes with his back, and so becomes free.