The posterior limbs of the Geotrupes stercorarius, "perfectly developed in the adult, are atrophied in the larvae, reduced to mere specks."
The general history of the species, of its migrations and its changes, will doubtless one day throw light upon these strange infirmities, here temporary and there permanent, which may perhaps be explained by unforeseen encounters with undiscovered specimens, strayed perhaps into distant countries. [(9/4.)]
What invaluable documents for the entomologist and the historian of the evolution of the species are those multiple and fabulous metamorphoses of the Sitares and the Meloïdae which this indefatigable inquirer has revealed in all their astonishing phases!
One of the finest examples of scientific investigation is the pursuit, through a period of twenty-five years, with a sagacity which seems to border on divination, of this problem of hyper-metamorphosis. The larvae of those coleoptera which we have seen introduced, with infernal cunning, into the cells of the Anthophora (See Chapter 8 above.), suffer no less than four moults before they become nymphs.
These merely external transformations, which involve only the envelope, and respect the internal structure, correspond each with a change of environment and of diet. Each time the organism adapts itself to its new mode of existence, "as perfectly as when it becomes adult"; and we see the insect, which was clear-sighted, become blind; it loses its feet, to recover them later; its slender body becomes ventripotent; hard, it grows soft; its mandibles, at first steely, become hollowed out spoonwise, each modification of conformation having its motive in a fresh modification of the conditions of the creature's life.
How explain this strange evolution of a fourfold larval existence, these successive appearances of organs, which become entirely unlike what they were, to serve functions each time different?
What is the reason, the intention, the high law which presides over these visible changes, these successive envelopments of creatures one within the other, these multiple transfigurations?
By what bygone adaptations has the Sitaris successively acquired these diverse extraordinary phases of life, indicating possibly for each corresponding age some ancient and remote heredity? [(9/5.)]
How many other arguments might evolution derive from his books, and what illustrations of the Darwinian philosophy has he unconsciously furnished! Does he not even allow the admission to escape him that "the spirit of cunning and deception is transmitted"? He sees in the persecutions of the Dytiscus, the "pirate of the ponds," the origin of the faculty which the Phryganea has of refashioning its shield when demanded of it. "To evade the assault of the brigand, the Phryganea must hastily abandon its mantle; it allows itself to sink to the bottom, and promptly removes itself; necessity is the mother of invention." [(9/6.)]
Returning to the lacunae which it so amazes Fabre to discover in our organization, even in the most perfect of us, are they fundamentally very real? These mysterious and unknown senses which he has so greatly contributed to elucidate in the case of the inferior species: why, he asks, have we not inherited them, if we are truly the final term and the supreme goal of creation?