’Tis Parnassius Apollo, the beautiful occupant of the Alpine solitudes, near the eternal snows. Her caterpillar lives on the saxifrages. Here let us end this sketch of the sweet joys that await the naturalist on the summit of Mont Ventoux and return to the Hairy Ammophila, who was lurking yesterday in her legions under the shelter of a stone when the misty rain came and enshrouded us. CHAPTER XII THE TRAVELLERS I have told in the last chapter how, on the ridges of Mont Ventoux, at a height of nearly 6000 feet, I had one of those entomological windfalls which would be rich in results if they occurred often enough to serve the purpose of continuous study. Unfortunately, mine was a solitary instance and I despair of ever repeating it. I can therefore only base conjectures on it, in the hope that future observers will replace my surmises with certainties. Under the shelter of a broad, flat stone I discovered some hundreds of Ammophilæ (A. hirsuta), heaped one on top of the other almost as closely as the Bees in a swarm. As soon as I lifted the stone, all this little hairy world began to run about, without making any attempt to fly away. I shifted the mass by handfuls: not one of the Wasps looked as though she wished to desert the rest. They seemed indissolubly united by common interests; none of them would go unless all went. I examined with every possible care the flat stone that sheltered them, as well as the ground underneath and just around it, and discovered not a thing to tell me the cause of this strange assemblage. Having nothing better left to do, I tried to count them; and it was then that the clouds came and put an end to my observations and plunged us into that darkness of which I have described the anxious consequences. At the first drops of rain, before leaving the spot, I hastened to put back the stone and replace the Ammophilæ in their shelter. I give myself a good mark, which I hope that the reader will confirm, for having taken the precaution not to leave the poor insects whom my curiosity had disturbed at the mercy of the downpour. The Hairy Ammophila is not rare in the plains, but she is always found singly by the side of the paths or on the sandy slopes, now engaged in digging her well, anon busily carting her heavy caterpillar. She lives alone, like the Languedocian Sphex; and it was a great surprise to me to come upon such a number of this species collected under one and the same stone almost at the top of Mont Ventoux. Instead of the isolated specimen which I had known hitherto, a crowded company presented itself to my eyes. Let us try to trace the probable causes of this agglomeration.