'The cotton-pressing females have the edge of their mandibles cut out into five or six little teeth, which make an instrument admirably suited for scraping and removing the hairs from the epidermis of the plants. It is a sort of comb or teasel. The resin-kneading females have the edge of the mandible not toothed, but simply curved; the tip alone, preceded by a notch which is pretty clearly marked in some species, forms a real tooth; but this tooth is blunt and does not project. The mandible, in short, is a kind of spoon perfectly fitted to remove the sticky matter and to shape it into a ball.' Nothing better could be said to explain the two sorts of industry: in the one case, a rake which gathers the wool; in the other, a spoon which scoops up the resin. I should have left it at that and felt quite content without further investigation, if I had not had the curiosity to open my boxes and, in my turn, to take a good look, side by side, at the workers in cement and the workers in cotton. Allow me, my learned master, to whisper in your ear what I saw. The first that I examine is Anthidium septemdentatum. A spoon: yes, it is just that. Powerful mandibles, shaped like an isosceles triangle, flat above, hollowed out below; and no indentations, none whatsoever. A splendid tool, as you say, for gathering the viscous pellet; quite as efficacious in its kind of work as is the rake of the toothed mandibles for gathering cotton. Here certainly is a creature potently-gifted, even though it be for a poor little task, the scooping up of two or three drops of glue. Things are not quite so satisfactory with the second Resin-bee of the Snail-shells, A. bellicosum. I find that she has three teeth to her mandibles. Still, they are slight and project very little. Let us say that this does not count, even though the work is exactly the same. With A. quadrilobum the whole thing breaks down. She, the queen of Resin-bees; she, who collects a lump of mastic the size of one's fist, enough to subdivide hundreds of her kinswomen's Snail-shells: well, she, by way of a spoon, carries a rake! On the wide edges of her mandibles stand four teeth, as long and pointed as those of the most zealous cotton-gleaner. A. florentinum, that mighty manufacturer of cotton-goods, can hardly rival her in respect of combing-tools. And nevertheless, with her toothed implement, a sort of saw, the Resin-bee collects her great heap of pitch, load by load; and the material is carried not rigid, but sticky, half-fluid, so that it may amalgamate with the previous lots and be fashioned into cells.