THE improvement which Prof. Newton's excellent edition of Mr. Yarrell's work is undergoing by passing through the hands of its accomplished and assiduous editor, is evident on every page, and the care with which the large mass of literature on the subject of most of the species has been studied, must be evident to all readers. The chief features of this part are the following. The author has entered with considerable detail into the puzzling question of those forms or species of blue-throat, Ruticilla suecica, R. leucocyana and R. wolfi—of which the first only can be said with certainty to have occurred in this country. The so-called “Melodious Willow Wren,” of which two examples have been met with in the British Isles, is shown on Mr. Dresser's authority to be the Icterine Warbler (Hypolais icterina), and its distinction from the nearly allied Polyglot Warbler (H. polyglotta) is carefully pointed out, and it may be mentioned that these two birds have only a superficial resemblance to the true Willow-wrens, among which they have been erroneously placed by most British authors. The evidence as to the occurrence of the Marsh Warbler (Acrocephalus palustris) in England is shown to be very defective, and the editor declines admitting it at present to our fauna. The Aquatic Warbler (A. aquaticus) on the other hand, seems to have been obtained some three if not four times. The history of that very interesting species Saddler's Warbler (A. luscinioides) is fully given, more so than is done in any other work with which we are acquainted. It was doubtless in former days a regular, though never a very abundant summer visitant to the eastern counties of England, until the drainage of the meres and fens unfitted wide districts for its habitation. The first example of the species ever brought to the notice of naturalists was obtained early in the present century by a party of Norfolk observers, including the late Sir William Hooker. This specimen was in 1816 shown to Temminck, then on a visit to London, and by him said to be a variety of the Reed Wren, a bird from which it may be fairly separated generically. Some years after, Sair described it from Italian examples, and it has always had the reputation of being a southern species. But it is to Englishmen that we owe nearly all the information we possess concerning it. Its nest and eggs were discovered near Cambridge in 1845, three years before anything was published about them on the Continent, and its peculiar habits have been chiefly described by Englishmen, from their own observation, whether in this country or abroad. The account of this species has been written de novo, and great pains has indeed been taken to bring the history of all the other birds treated in this part (fourteen in number) up to our present state of knowledge of them.