To thwart this vigilance, the real enemies need to be masters of the art of stealthy immobility and cunning dissimulation. But there is no dissimulation about the Volucella-grub. It comes and goes, openly, wheresoever it will; it looks round amongst the Wasps for cells to suit it. What has it to make itself thus respected? Strength? Certainly not. It is a harmless creature, which the Wasp could rip open with a blow of her shears, while a touch of the sting would mean lightning death. It is a familiar guest, to whom no denizen of a Wasp’-nest bears ill-will. Why? Because it renders good service: so far from working mischief, it does the scavenging. Were it an enemy or merely an intruder, it would be exterminated; as a deserving assistant it is respected. Then what need is there for the Volucella to disguise herself as a Wasp? Any Fly, whether grey or motley, is admitted to the burrow directly she makes herself useful to the community. The mimicry of the Volucella, which was said to be one of the most conclusive cases, is, after all, a mere childish notion. Patient observation, continually face to face with facts, will have none of it and leaves it to the arm-chair naturalists, who are too prone to look at the animal world through the illusive mists of theory. NOTES [1] I include three species promiscuously under this one name, that is to say, E. pomiformis, Fabr., E. bipunctis, Sauss., and E. dubius, Sauss. As I did not distinguish between them in my first investigations, which date a very long time back, it is not possible for me to-day to attribute to each of them its respective nest. But their habits are the same, for which reason this confusion does not injure the order of ideas in the present chapter.—Author’s Note. [2] The Grey Worm is the caterpillar of Noctua segetum, the Dart or Turnip Moth. It is hunted by the Hairy Ammophila, for whom cf. The Hunting Wasps, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chap. xviii.—Translator’s Note. [3] Cf. The Hunting Wasps: passim; Insect Life, by J. H. Fabre, translated by the author of Mademoiselle Mori: chaps. iii. to xii., xiv. to xvii. and xix.; The Life and Love of the Insect, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chaps. xi. to xii.; and Social Life of the Insect World, by J. H. Fabre, translated by Bernard Miall: chap. xiii.—Translator’s Note. [4] Marcus Vitruvius Pollio, the Roman architect and engineer.—Translator’s Note. [5] Cf. The Mason-bees, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chaps. i. to iii. et passim.—Translator’s Note. [6] .63 inch to .7 inch.—Translator’s Note. [7] .12 inch.—Translator’s Note. [8] Also known as the Measuring-worm, the caterpillar of the Geometrid Moth.—Translator’s Note. [9] .585 inch.—Translator’s Note. [10] .098 inch.—Translator’s Note. [11] .27 by .50 inch.—Translator’s Note.