An animal is a structure capable of becoming more spacious with the same amount of materials. Everything depends upon the molecular architecture, which becomes more and more refined by the tremors of life. The contents of the egg, a compact mass, expand into a creature which is all the bulkier for its richness in organs for diverse functions. Even so, the locomotive engine, the creature of industry, occupies more space than the iron, its raw material, melted down into a single ingot. When the shell is able to stretch, the egg swells under the thrust of its contents, which form into an organic whole and dilate. This is the case with the various Dung-beetles. When the shell is hard and rigid, a void is made by evaporation at the thick end; and this excess of space supplies the room necessary for the increase in volume of the contents. This is the case with the birds, which develop within a chalky enclosure that does not alter in size. Both of them dilate, with this difference that the soft shell allows the inside work to be perceived outside, whereas the stiff shell reveals nothing. Lastly, the hatching does not always stop the growth that is not preceded by feeding. For a little while longer the larva continues to increase in size; it completes the work of acquiring stability in its new equilibrium, the equilibrium of a living creature; it improves its physique by supplementary stretching. The Scorpion has already told us this; the grub of the Minotaurus and many others assure us of the same thing. It is, on a smaller scale, what we saw before in the Locust’s wing, [64] which, issuing from a very small sheath, soon unfurls into a sail of generous breadth. Twice, therefore, am I changing my opinions in this history of the Dung-beetles: first, on the subject of the paste spread on the walls of the natal chamber; secondly, on the subject of the egg that increases in size after it is laid. I have corrected my statements without being greatly ashamed of my mistakes, for it is difficult indeed to reach the vein of truth at the first tentative boring. There is only one means of never blundering, which is never to do anything and, above all, to let ideas alone. CHAPTER XVIII THE BULL ONTHOPHAGUS: THE LARVA; THE NYMPH May is the nesting-month of the different Onthophagi and of the Bull Onthophagus in particular. The mothers now go underground to some little depth, under the shelter of the cave whence the building and victualling-materials are extracted. Unaided by the males, who, heedless of family cares, continue to lead a life of jollity, they fashion their cabins and stuff them with provisions after the egg is laid. The work, for that matter, is crude and elementary and hardly needs the collaboration of the horned dandies. Five or six establishments at most, each founded in a couple of days, represent the whole of a mother’s work and leave plenty of time for spring revelry.