species and even the sexes keeping distinct: this shows arrangement, a plan, a special course of procedure—a preparation for the great event shortly to come off. That birds too, under certain circumstances, should delay their flight waiting for a more favourable wind, shows a high degree of intelligence.
An experience of more than twenty years close observation of the habits and manners of birds, more particularly in connection with their annual migrations, has led me to the conclusion that they not only possess far more intelligence than we usually give them credit for, but also know how to make the best use of this intelligence. They do not move in a groove, and are not the mere blind subjects of a great mundane law which Mr. Rowley would seem to infer.
It is a well-established fact that the same birds, both during the vernal and autumnal migration, do return in a great number of instances to the same place. The cases indeed recorded are so numerous that I have difficulty in making a selection. The well-known fact of a Wagtail's nest being built year after year in a particular place, and of a Cuckoo laying her eggs in that nest almost year by year, is one instance. Perhaps, however, the most remarkable case is that mentioned by Mr. Stevenson ('Birds of Norfolk,' vol. ii., p. 55), and previously recorded by Mr. Hewitson ('Eggs of British Birds,' vol. i., p. 209), on the authority of Professor Newton, of a pair of Stone Curlews continuing to resort, year after year, to nest in one particular place (though it was entirely changed in character), long after it, and many acres around it, was planted with trees, and had become the centre of a flourishing wood—namely, the Warren Wood of Elveden, near Thetford, which extends over more than three hundred acres.
In Professor Newton's new edition of Yarrell (p. 565, note), another curious instance is given in the case of several pairs of the Yellow Wagtail (Motacilla Raii) returning year by year to nest in the same haunts, some heathery mounds bordering a stretch of wet meadows on the left bank of the Little Ouse, below Thetford. The whole passage may be commended to the reader's notice.
At the Ashby decoy, Lincolnshire, a particularly marked duck, having a white throat, was known to come in eight winters in succession, and another, a spotted duck, for four or five years. These, and numbers of other cases, which time and space will not
