Be this as it may, the bee in question having selected a place suitably sheltered from the weather, and from the intrusion of depredators, proceeds to form her nest, the exterior walls of which she forms of the wool of pubescent plants, such as rose-campion (_Lychnis coronaria_), the quince (_Pyrus cydonia_), cats-ears (_Stachys lunata_), &c. "It is very pleasant," says Mr. White, of Selborne, "to see with what address this insect strips off the down, running from the top to the bottom of the branch, and shaving it bare with all the dexterity of a hoop-shaver. When it has got a vast bundle, almost as large as itself, it flies away, holding it secure between its chin and its fore-legs."[Q] The material is rolled up like a ribbon; and we possess a specimen in which one of these rolls still adheres to a rose-campion stem, the bee having been scared away before obtaining her load. The manner in which the cells of the nest are made seems not to be very clearly understood. M. Latreille says, that, after constructing her nest of the down of quince-leaves, she deposits her eggs, together with a store of paste, formed of the pollen of flowers, for nourishing the grubs. Kirby and Spence, on the other hand, tell us, that "the parent bee, _after_ having constructed her cells, laid an egg in each, and filled them with a store of suitable food, plasters them with a covering of vermiform masses, apparently composed of honey and pollen; and having done this, aware, long before Count Rumford's experiments, what materials conduct heat most slowly," she collects the down from woolly plants, and "sticks it upon the plaster that covers her cells, and thus closely envelops them with a warm coating of down, impervious to every change of temperature." "From later observations," however, they are "inclined to think that these cells may possibly, as in the case of the humble-bee, be in fact formed by the larva previously to becoming a pupa, after having eaten the provision of pollen and honey with which the parent bee had surrounded it. The vermicular shape, however, of the masses with which the cases are surrounded, does not seem easily reconcilable with this supposition, unless they are considered as the excrement of the larva."[R] Whether or not this second explanation is the true one, we have not the means of ascertaining; but we are almost certain the first is incorrect, as it is contrary to the regular procedure of insects to begin with the interior part of any structure, and work outwards. We should imagine, then, that the down is first spread out into the form required, and afterwards plastered on the inside to keep it in form, when probably the grub spins the vermicular cells previous to its metamorphosis.