By what inconceivable inspiration does the Cerceris[6] leave the refreshment-bar of the blossoms, dripping with nectar, to go a-hunting and to slay the Weevil, the game destined for her offspring? How are we to explain the Sphex, who, having refreshed herself at the sugar-works of the field eringo, suddenly flies off, eager to stab the Cricket, the food of her grub?
It is a matter of memory, some will make haste to reply.
Ah no! Please do not speak of memory here; do not appeal to the belly’s powers of reminiscence! Man is fairly well endowed with mnemonic aptitudes. Yet which of us has retained the least [[64]]recollection of his mother’s milk? If we had never seen a babe at the breast, we could never suspect that we began life in the same fashion.
This food of earliest infancy is not remembered; it is certified only by example, as by that of the Lamb, which, with bended knees and frisking tail, sucks at the udder and butts it with its head. No, the mouthfuls of mother’s milk have left not a trace in the mind.
And you would have it that the insect, after a transformation that has changed it entirely, both inside and out, remembers its first diet, when we ourselves, who are not remoulded in the crucible of a metamorphosis, remain in the most absolute darkness where ours is concerned! My credulity will not go to that length.
How then does the mother, whose diet is different, distinguish what suits her offspring? I do not know, I never shall know. It is an inviolable secret. The mother herself does not know. What does the stomach know of its masterly chemistry? Nothing. What does the heart know of its wonderful hydraulics? Nothing. The pregnant mother, when establishing her brood, knows no more.
And this unconsciousness provides us with an admirable solution of the difficult problem of victuals. A good example is afforded by the Weevils whom we have just been considering. They will show us with what botanical tact the choice of the food-plant is made. [[65]]
To entrust the batch of eggs to this or that cluster of florets is not a matter of indifference. It is indispensable that the florets should fulfil certain conditions of flavour, stability, hairiness, and other qualities appreciated by the grub. Its selection, therefore, demands a nice botanical discrimination which will recognize off-hand the good and the bad, accept the discovery or reject it. Let us devote a few lines to these Weevils from the point of view of their botanical attainments.
Scorning variety, the Spotted Larinus is a specialist of immovable convictions. Her domain is the blue ball of the echinops, an exclusive domain, valueless to the others. She alone appreciates it, she alone exploits it; and nothing else suits her.
This particularity, an unchangeable family inheritance, must greatly facilitate her search. When, on the return of the warm weather, the insect leaves her hiding-place, which is doubtless not far from the spot where she was born, she easily finds, on the banks by the road-side, her favourite plant, which is already tipping its branches with pale-blue globes. The dear heritage is recognized without hesitation. She climbs into it, rejoices in her nuptial diversions and waits for the azure balls to mature to the requisite stage. The blue thistle is familiar to her though she sees it for the first time. It was the only one known in the past; it is the only one known in the present. There is no confusion possible. [[66]]