The Sparrow shall tell us first how his nest-building art stood in the days when there were no lodgings in walls and roofs. A hollow in a tree, high enough to shelter him from prying eyes, with a narrow mouth to keep out the rain and a fairly generous cavity, gives him an excellent dwelling, of which he readily avails himself even when there are plenty of old walls and roofs in the neighbourhood. The youngest bird’s-nester in my village knows all about it and abuses his knowledge. The hollow tree then is one lodging which the Sparrow employed, long before using Evander’s cabin and David’s stronghold on the rock of Zion. His architectural resources go even further. His shapeless mattress, an incoherent jumble of feathers, down, flock, straw and other incongruous materials, seems to demand a broad and stable support. The Sparrow laughs at the difficulty and, from time to time, for reasons that remain hidden from me, he conceives a bold plan: he decides to build a nest having no support but that of three or four tiny branches at the top of a tree. The clumsy maker of mattresses tries to obtain aerial suspension, a swinging house, the prerogative of weavers and basket-makers well-versed in the art of plaiting. And he succeeds. In the fork of a few branches he accumulates everything suitable for his work that he can pick up near a house: rags, scraps of paper, ends of thread, flocks of wool, bits of hay and straw, dry blades of grass, flax dropped from the distaff, strips of bark retted by lying long in the open; and of his various gleanings, clumsily matted together, he contrives to make a large, hollow ball with a narrow opening in the side. It is bulky to a degree, the thickness of the dome having to be as good a defence against the rain as the shelter of a tile would be; it is very roughly constructed, without any attempt at artistry; but, when all is said, it is stout enough to last for a season. This is how the Sparrow must have worked in the beginning, when there was no hollow tree at hand. Nowadays, that primitive art, too costly in time and materials, is seldom practised.