picks up a leaf, again walks on for a little, drops it, and disappears with quick darting flight after another—probably rival—male. Presently he returns, crawls to the top of a bush, commences to sing, in the middle suddenly breaks off, and again darts off after the other male, then returns and marches on in front of the female, and again picks up and carries a leaf. She meanwhile threads her way in and out of the dead and growing herbage, apparently unconscious to anything that might in any way tend to produce the same nervous tension in her own mind, and oblivious to the sexual selection proceeding around her. In fact, I cannot call to mind a single case where I have seen anything approaching frenzy in the female of any species while mating.
The conclusion I formed after remarking the behaviour of the males at this season was that the picking up and carrying of a leaf was due solely to the fact that, inasmuch as the construction of the nest must be commenced within a few days of the time of my observations, and the bird's mind being full also of this same idea, this action might be ipso facto a commencement; but, in the light of later observations, any theory of this kind falls to the ground. The following spring I was attracted by the movements of a Blackcap flying from tree to tree in hurried flight, carrying a piece of one of the dead grasses with which the nest is generally constructed. But herein lies the difference—that it was one of the first Blackcaps that had arrived, and there was no sign of any female; in fact, the females had not arrived. Again, last year, the first Whitethroat arrived in this district—and how well I remember the day—on the 20th April, the first day of that long spell of dry weather. The sun was just rising, and the rays of light coming through a slight mist gave all the trees and foliage that extraordinary glow which those who are accustomed to being out at that time of day will readily understand. Not having seen the bird for six or seven months, I thought I must sit down and watch. The bird was in that state of restless frenzy, at one moment diving into a bramble-bush, then climbing up the topmost sprays, singing all the while intermittently. After one rather longer dive into the bush than usual, he reappeared, carrying a piece of dead grass in his bill, full of excitement, flying from spray to spray, with no apparent object
