Being a very bold bird, and not much afraid of man, it allows a careful observer to watch its movements clearly. I have often stood close to the tree round which several Nightjars were circling, and seen them chase their prey to the ground within a yard or two of the spot on which I was standing. The flight of the Nightjar is singularly graceful. Swift as the swallow itself, it presents a command of wing that is really wonderful, gliding through the air with consummate ease, wheeling and doubling in pursuit of some active moth, whose white wings glitter against the dark background, while the sober plumage of its pursuer is scarcely visible, passing often within a few feet of the spectator, and yet not a sound or a rustle will reach his ears. Sometimes the bird is said to strike its wings together over its back, so as to produce a sharp snapping sound, intended to express anger at the presence of the intruder. I never, however, heard this sound, though I have watched the bird so often. Owing to the soft plumage with which it is clad, this bird, like the owls, looks larger than really is the case. It is between ten and eleven inches in length, with an expanse of wing of twenty inches, and yet weighs rather less than three ounces. Its large mouth, like that of the swallow tribe, opens as far as the eyes, and is furnished with a set of _vibrissæ_ or bristles, which remind the observer of the "whale-bone" which is set on the jaw of the Greenland whale. [Illustration: trees and bird] [Illustration: swallow] THE SWALLOW. Identification of the smaller birds--Oriental indifference to natural history--Use of collective terms--The Swallow--The Bird of Liberty--Swallows and Swifts--Variety of small birds found in Palestine--The Swallows of Palestine. Difficult as is the identification of the mammalia mentioned in the Bible, that of the birds is much more intricate. Some of the larger birds can be identified with tolerable certainty, but when we come to the smaller and less conspicuous species, we are at once lost in uncertainty, and at the best can only offer conjectures. The fact is, the Jews of old had no idea of discriminating between the smaller birds, unless they happened to be tolerably conspicuous by plumage or by voice. We need not be much surprised at this. The Orientals of the present day do precisely the same thing, and not only fail to discriminate between the smaller birds, but absolutely have no names for them.