Fabre, Poet of Science

by Georges Victor Legros

But Fabre will suppose nothing; he will only record the facts. Instead of wandering in the region of probabilities, he prefers to confine himself to the reality, and for the rest to reply simply that "we do not know."

This stern, positive, rigorous, independent, and observant mind, nourished upon geometry and the exact sciences, which has never been able to content itself with approximations and probabilities, could but distrust the seductions of hypotheses.

His robust common sense, which was always his protection against precipitate conclusions, too clearly comprehends the limits of science and the necessity of accumulating facts "upon the thorny path of observation and experiment" to indulge in generalization. He feels that life has secrets which our minds are powerless to probe, and that "human knowledge will be erased from the archives of the world before we know the last word concerning the smallest fly."

This is why he was regarded as "suspect" by the company of official scientists, to whom he was a dissenter, almost a traitor, especially at a moment when the theories of evolution, then in the first flush of their novelty, were everywhere the cause of a general elation.

No one as yet was capable of divining the man of the future in this modest thinker who would not accept the word of the masters interested, but in opposing the theory of transformation, far from being reactionary, Fabre revealed himself, at least in the domain of animal psychology, as an innovator, a true precursor.

Moreover, his observations, always so direct and personal, often revealed the contrary of what was asserted or foreseen by the magic formulae suggested by the mind.

To the ingenious mechanism invented by the transformists he preferred to oppose, not contrary argument, but the naked undeniable fact, the obvious testimony, the certain and irrefragable example. "Is it," he would ask them, "to repulse their enemies that certain caterpillars smear themselves with a corrosive product? But the larva of the Calosoma sycophanta, which feeds on the Processional caterpillar of the oak-tree, pays no heed to it, neither does the Dermestes, which feeds on the entrails of the Processional caterpillar of the pine-tree."

And consider mimicry. According to the theory of evolution, certain insects would utilize their resemblance to certain others in order to conceal themselves, and to introduce themselves into the dwellings of the latter as parasites living at their expense. Such would be the case with the Volucella, a large fly whose costume, striped with brown and yellow bands, gives it a rude resemblance to the wasp. Obliged, if not for its own sake at least for that of its family, to force itself into the wasp's dwelling as a parasite, it deceitfully dresses itself, we are told, in the livery of its victim, thus affording the most curious and striking example of mimicry; and naturalists insufficiently informed would regard it as one of the greatest triumphs of evolution.

Now what does the Volucella do? It is true that it lays its eggs without being disturbed in the nest of the wasp. But, as the rigorous observer will tell you, it is a precious auxiliary and not an enemy of the community. Its grubs, far from disguising or concealing themselves, "come and go openly upon the combs, although every stranger is immediately massacred and thrown out." Moreover, "they watch the hygiene of the city by clearing the nest of its dead and ridding the larvae of the wasps of their excretory products." Plunging successively into each chamber of the dormitory the forepart of their bodies, "they provoke the emission of that fluid excrement of which the larvae, owing to their cloistration, contain an extreme reserve." In a word, the grubs of the Volucella "are the nurses of the larvae," performing the most intimate duties." [(9/1.)]

What an astonishing conclusion! What a disconcerting and unexpected reply to the "theories in vogue"!