The Life of the Caterpillar

by Jean-Henri Fabre

Why should not some of the insects that dote on the smell of the dead have similar habits? Dermestes and Saprini come to the dragon arum; all day long they swarm in throngs, although free to go away; many of them die in the riot of the orgy. It is no rich provender that keeps them, for the flower gives them nothing to eat; it is not a question of laying eggs, for they take good care not to settle their grubs in that famine-stricken spot. What are they doing here, the frenzied ones? Apparently intoxicating themselves with fetidness, just as Bull did on the carcass of a Mole.

And this intoxication of smell attracts them from every part around, from very far perhaps, one cannot tell. Even so the Necrophori, [[326]]in quest of an establishment for their young, hasten from the fields to my putrefying Moles. Both are informed by a potent smell, which offends our nostrils sixty yards away, but which travels ahead and delights them at distances where our own power of scent ceases.

The hydnocystis, the Bolboceras’ treat, has none of these violent emanations, capable of being diffused through space; it is devoid of smell, at least to us. The insect that hunts for it does not come from a distance; it inhabits the very places where the cryptogam lies. However faint the effluvia of the underground morsel, the prying epicure, equipped for the purpose, has every facility for perceiving them: he operates close by, on the surface of the soil. The Dog’s case is the same: he goes along searching, with his nose to the ground. Then, too, the real truffle, the essential object of his quest, possesses a most pronounced odour.

But what are we to say of the Great Peacock and the Banded Monk, making their way to the female born in captivity? They hasten from the ends of the horizon. What do they perceive at that distance? Is it really [[327]]an odour, as our physiology understands the word? I cannot bring myself to believe it.

The Dog smells the truffle by sniffing the earth, quite close to the tuber; he finds his master at great distances by consulting the scent of his footprints. But is he able to discover the truffle hundreds of yards away, miles away? Can he join his master in the complete absence of a trail? Certainly not. For all his fineness of scent, the Dog is incapable of such a feat, which is performed, however by the Moth, who is put off neither by distance nor by the lack of any traces out of doors of the female hatched on my table.

It is a recognized fact that smell, ordinary smell, the smell that affects our nostrils, consists of molecules emanating from the scented body. The odorous matter dissolves and is diffused throughout the air by communicating to the air its aroma, even as sugar dissolves and is diffused in water by communicating to the water its sweetness. Smell and taste touch each other at some points; in both cases there is a contact between the material particles that give the impression and the sensitive papillæ that receive it.

Nothing can be simpler or clearer than that [[328]]the dragon arum elaborates an intensely strong essence with which the air is impregnated and infected all around. Thus the Dermestes and Saprini, those passionate lovers of carrion smells, are informed by molecular diffusion. In the same way, the putrid Toad gives out and disseminates the stinking atoms that are the Necrophorus’ delight.

But what is materially emitted by the female Bombyx or Great Peacock? Nothing, according to our sense of smell. And this nothing is supposed, when the males congregate, to saturate an immense circle, several miles in radius, with its molecules! What the horrible stench of the dragon arum is unable to do the absence of odour is believed to accomplish! However divisible matter may be, the mind refuses to accept such conclusions. It would be tantamount to reddening a lake with an atom of carmine, to filling immensity with nothing.

Another argument. When my study is saturated beforehand with pungent odours which ought to overcome and destroy the most delicate effluvia, the male Moths arrive without the least sign of embarrassment.

A loud noise kills the faint note and prevents [[329]]it from being heard; a bright light eclipses a feeble gleam. These are waves of the same nature. But the roar of thunder cannot cause the least jet of light to pale; nor can the dazzling glory of the sun stifle the least sound. Being of different natures, light and sound do not influence each other.