A like migration to a short distance seems to me to have caused the assemblage of Ammophila on the top of Mont Ventoux. I have proved that this insect spends the winter in the perfect state, sheltering somewhere and awaiting April to build its nest. Like the lark it must take precautions against the cold season; though capable of fasting till flowers return, the chilly thing must find protection against the deadly attacks of the cold. It must flee snowy districts, where the soil is deeply frozen, and, gathering in troops like migrant birds, cross hill and dale to seek a home in old walls and banks warmed by a southern sun. When the cold is gone, all or part of the band will return whence they came. This would explain the assemblage on Mont Ventoux. It was a migrant tribe, which, on its way from the cold land of the Drôme to descend into the warm plains of the olive, had to cross the deep, wide valley of the Toulourenc, and, surprised by the rain, halted on the mountain top. Apparently A. hirsuta has to migrate to escape winter cold. When the small migratory birds set out in flocks, it too must journey from a cold district to a neighbouring one which is warmer. Some valleys crossed, some mountains overpassed, and it finds the climate sought. I have two other instances of extraordinary insect gatherings at great heights. I have seen the chapel on Mont Ventoux covered with seven-spotted ladybirds, as they are popularly called. These insects clung to the stone of walls and pavement so close together that the rude building looked, at a few paces off, like an object made of coral beads. I should not dare to say how many myriads were assembled there. Certainly it was not food which had attracted these eaters of Aphidæ to the top of Mont Ventoux, some 6000 feet high. Vegetation is too scanty—never Aphis ventured up there. Another time, in June, on the tableland of St. Amand, at a height of 734 mètres, I saw a similar gathering, only less numerous. At the most projecting part of the tableland, on the edge of an escarpment of perpendicular rocks, rises a cross with a pedestal of hewn stone. On every side of this pedestal, and on the rocks serving as its base, the very same beetle, the seven-spotted ladybird of Mont Ventoux, was gathered in legions. They were mostly quite still, but wherever the sunbeams struck there was a continuous exchange of place between the newcomers, who wanted to find room, and those resting, who took wing only to return after a short flight. Neither here any more than on the top of Mont Ventoux was there anything to explain the cause of these strange assemblages on arid spots without Aphidæ and noways attractive to Coccinellidæ,—nothing which could suggest the secret of these populous gatherings upon masonry standing at so great an elevation.