Have we here two examples of insect migration? Can there be a general meeting such as swallows hold before the day of their common departure? Were these rendezvous whence the cloud of ladybirds were to seek some district richer in food? It may be so, but it is very extraordinary. The ladybird has never been talked of for her love of travel. She seems a home-loving creature enough when we see her slaying the green-fly on rose trees, and black-fly on beans, and yet with her short wings she mounts to the top of Ventoux and holds a general assembly where the swallow herself only ascends in her wildest flights. Why these gatherings at such heights? Why this liking for blocks of masonry? XV THE AMMOPHILA A slender waist, a slim shape, an abdomen much compressed at the upper part, and seemingly attached to the body by a mere thread, a black robe with a red scarf on its under parts,—such is the description of these Fossors; like Sphegidæ in form and colouring, but very different in habits. The Sphegidæ hunt Orthoptera, crickets, ephippigers, and grasshoppers, while the Ammophila chases caterpillars. This difference of prey at once suggests new methods in the murderous tactics of instinct. Did not the name sound pleasant to the ear, I should be inclined to quarrel with Ammophila, which means sand-lover, as being too exclusive and often erroneous. The true lovers of sand—dry, powdery, and slippery sand—are the Bembex, which prey on flies: but the caterpillar-hunters, whose history I am about to tell, have no liking for pure, loose sand, and even avoid it as being too subject to landslips which may be caused by a mere trifle. Their vertical pits, which must remain open until the cell is stored with food and an egg, require more solid materials if they are not to be blocked prematurely. What they want is a light soil, easy to mine, where the sandy element is cemented by a little clay and lime. The edges of paths—slopes of thin grass exposed to the sun,—such are the places they favour. In spring, from the first days of April, one sees Ammophila hirsuta there; in September and October there are A. sabulosa, A. argentata, and A. holosericea. I will make an abstract of the notes furnished by these four species.