I can assert to-day, after a long experience, that only the Social Hymenoptera, the Hive-bees, the Common Wasps, and the Bumble-bees know how to devise a common defence; and only they dare fall singly upon the aggressor, to wreak an individual vengeance. But we would not leave the banks of the “Sunken Road,” which have been made classic by Fabre’s observations on the Cerceris, the Sitaris and tutti quanti, without letting the reader hear an echo of the heartfelt accents in which the now ageing scientist speaks of these spots which witnessed his first endeavours and his first achievements as an entomologist, when he returns to them thirty years later to complete his data respecting the Anthophora’s parasites: Illustrious ravines whose banks are calcined by the sun, if I have in some small degree contributed to your fame, you, in your turn, have afforded me some happy hours of oblivion spent in the joy of learning. You, at least, have never lured me with vain hopes; all that you have promised me you have given me, often a hundredfold. You are my promised land, in which I fain would finally have pitched my observer’s tent. It has not been possible to realise my desire. Let me at least salute in passing my beloved insects of other days. A wave of the hat to the Tuberculated Cerceris, which I see on yonder bank busied with warehousing her Cleonus. As I saw her long ago, so I see her to-day.... Watching her at work, a younger blood flows in my veins; I scent, as it were, the fragrance of some renewal of life. But time passes; let us pass on. Yet another greeting here. I hear rustling overhead, above that ledge, a community of Sphex-wasps, stabbing their Crickets! Let us give them a friendly glance, but no more. My acquaintances here are too numerous: I have not time to resume all my old relations. Without stopping, a wave of the hat to the Eumenes ... the Philanthus ... the Tachytes.... At last we are there! [55] This last exclamation, a cry from the heart, which reveals the object of this latest visit, is addressed to the murmuring city of the Anthophoræ, in which he had formerly made such valuable discoveries, and in which there was still something left to discover: so true is it that even in those regions which have been most fully explored the scientist worthy of the name never flatters himself that he has reached the final limits of knowledge. CHAPTER XI THE PROFESSOR: AVIGNON (CONTINUED)