Like the Osmiae and the Leaf-cutters, the Anthidium shows an urgent need of a ready-made home. She never houses herself at her own expense. Can we discover the reason? Let us first consult a few hard workers who are artificers of their own dwellings. The Anthophora digs corridors and cells in the road-side banks hardened by the sun; she does not erect, she excavates; she does not build, she clears. Toiling away with her mandibles, atom by atom, she manages to contrive the passages and chambers necessary for her eggs; and a huge business it is. She has, in addition, to polish and glaze the rough sides of her tunnels. What would happen if, after obtaining a home by dint of long-continued toil, she had next to line it with wadding, to gather the fibrous down from cottony plants and to felt it into bags suitable for the honey-paste? The hard-working Bee would not be equal to producing all these refinements. Her mining calls for too great an expenditure of time and strength to leave her the leisure for luxurious furnishing. Chambers and corridors, therefore, will remain bare. The Carpenter-bee gives us the same answer. When with her joiner's wimble she has patiently bored the beam to a depth of nine inches, would she be able to cut out and place in position the thousand and one pieces which the Silky Leaf-cutter employs for her nest? Time would fail her, even as it would fail a Megachile who, lacking the Capricorn's chamber, had herself to dig a home in the trunk of the oak. Therefore the Carpenter-bee, after the tedious work of boring, gets the installation done in the most summary fashion, simply running up a sawdust partition. The two things, the laborious business of obtaining a lodging and the artistic work of furnishing, seem unable to go together. With the insect as with man, he who builds the house does not furnish it, he who furnishes it does not build it. To each his share, because of lack of time. Division of labour, the mother of the arts, makes the workman excel in his department; one man for the whole work would mean stagnation, the worker never getting beyond his first crude attempts. Animal industry is a little like our own: it does not attain its perfection save with the aid of obscure toilers, who, without knowing it, prepare the final masterpiece. I see no other reason for this need of a gratuitous lodging for the Megachile's leafy basket or the Anthidia's cotton purses. In the case of other artists who handle delicate things that require protection, I do not hesitate to assume the existence of a ready-made home. Thus Reaumur tells us of the Upholsterer-bee, Anthocopa papaveris, who fashions her cells with poppy-petals. I do not know the flower-cutter, I have never seen her; but her art tells me plainly enough that she must establish herself in some gallery wrought by others, as, for instance, in an Earth-worm's burrow.