They build, so far as I know, always in holes, in trees, rocks, and walls, preferentially in the latter. Their nests involve generally two different kinds of work--the working up of the true nests on which the eggs repose, and the preliminary closing in and making comfortable the cavity in which the former is placed. For this latter work they use almost exclusively moss. Sometimes very little filling-in is required; sometimes the mass of moss used to level and close in an awkward-shaped recess is surprisingly great. A pair breed every year in a terrace-wall of my garden at Simla; elevation about 7800 feet. One year they selected an opening a foot high and 6 inches wide, and they closed up the whole of this, leaving an entrance not 2 inches in diameter. Some years ago I disturbed them there, and found nearly half a cubic foot of dry green moss. Now they build in a cavity behind one of the stones, the entrance to which is barely an inch wide, and in this, as far as I can see, they have no moss at all. The nests are nothing but larger or smaller pads of closely felted wool and fur; sometimes a little moss, and sometimes a little vegetable down, is mingled in the moss, but the great body of the material is always wool and fur. They vary very much in size: you may meet with them fully 5 inches in diameter and 2 inches thick, comparatively loosely and coarsely massed together; and you may meet with them shallow saucers 3 inches in diameter and barely half an inch in thickness anywhere, as closely felted as if manufactured by human agency. Six to eight is considered the full complement of eggs, but the number is very variable, and I have taken three, four, and five well-incubated eggs. Captain Beavan, to judge from his description, seems to have found a regular cup-shaped nest such, as I have never seen. He says:--"At Simla, April 20th, 1866, I found a nest of this species with young ones in it in an old wall in the garden. I secured the old bird for identification, and then released her. The nest contained seven young ones, and was large in proportion. The outside and bottom consists of the softest moss, the nest being carefully built between two stones, about a foot inside the wall; the rest of it is composed of the finest grey wool or fur. Diameter inside 2·5; outside about 5 inches. Depth inside nearly 3 inches; outside 3·6." Captain Cock told me that he "found several nests in May and June in Cashmere. The first nest I found was in a natural cavity high up in a tree, containing three eggs, which I unfortunately broke while taking them out of the nest. The interior of the cavity was thickly lined with fur from some small animal, such as a hare or rat. I found my second nest close to my tent in a cleft of a pine, quite low down, only 3 feet from the ground. I cut it out and it contained five eggs of the usual type--broad, blunt little eggs, white, with rusty blotches."