But my ambition was far from satisfied. It was not enough to know ravisher and prey: I wanted the larva for which all this rich store was laid up. After exhausting the first vein of Buprestis I hastened to make new excavations. Digging down more carefully I finally discovered two larvæ, which completed the good fortune of this campaign. In less than an hour I turned over three haunts of the Cerceris, and my booty was some fifteen whole Buprestids with fragments of a yet greater number. I calculated, and I believe it fell far short of the truth, that there were twenty-five nests in this garden, a fact representing an immense number of buried Buprestids. What must it be, I said to myself, in localities where in a few hours I have caught as many as sixty Cerceris on blossoming garlic, with nests most probably near, and no doubt provisioned quite as abundantly! Imagination, backed by probability, showed me underground, within a small space, B. bifasciata by thousands, although I who have observed the entomology of our parts for over thirty years have never noticed a single one. Once only, perhaps twenty years ago, did I see, sticking in a hole of an ancient oak, the abdomen and elytra of this insect. This fact was a ray of light, for it told me that the larva of B. bifasciata must live in the wood of the oak, and entirely explained the abundance of this beetle in a district where the forests consist chiefly of that tree. As Cerceris bupresticida is rare on the clayey hills of the latter stretch of country compared to the sandy plains where grows Pinus maritima, it became an interesting question whether this Hymenopteron when it inhabits the pine region provisions its nest as it does in the oak district. I had good reason to believe that it did not, and you will soon see with some surprise how exquisite is the entomological tact of our Cerceris in her choice of the numerous kind of Buprestids.