In the most recently published list of European birds fifty-two species of birds of prey are given as occurring more or less frequently within the limits of our continent. Of the three generally-recognised species of European Vultures two are well represented, as regards their eggs, in the Wolleyan series. A few years ago the nesting of all these birds was utterly unknown to naturalists, and it was mainly through the exertions of Mr. Wolley and his friends that specimens first reached our collectors' cabinets. Here were found both the Egyptian Vulture and the Griffon breeding abundantly in the Eastern Atlas in 1857; and the eyries of these birds have since been visited by other collectors in the same country. The Eggs of the former of these Vultures are remarkable for their deep and rich coloration. The productions of the Griffon are not nearly so handsome, and are occasionally altogether destitute of markings. Of the Eagles of Europe the series of Eggs is very full, especially of the two well-known British species--the Golden Eagle and Sea Eagle. The Golden or Mountain Eagle is even now-a-days much more common in the remote parts of the British islands than is usually supposed to be the case. In 1852 Mr. Wolley was acquainted with five nests of this bird in various parts of Scotland, and there were undoubtedly at least as many more of which he did not learn the particulars. The eyrie is usually placed in some mountainous district, on the ledge of some "warm-looking" rock, well clothed with vegetation, and often by no means wild or exposed. Not unfrequently, under proper guidance, one can walk into the nest almost without climbing. Mr. Newton gives a very entertaining account of the taking of a pair of eggs from a nest in Argyllshire in 1861, where this seems to have been the case. In the whole ascent there was only one "ticklish place," where it was necessary to go sideways on a narrow ledge round some rocks. The Sea Eagle, on the other hand, generally breeds on the high cliffs upon the coast, often selecting the most inaccessible position for its eyrie. Sometimes, however, it will choose an island in the middle of an inland loch, and in such case places its nest upon the ground or in a tree. Mr. Wolley's well-written notes of his adventures in quest of both these Eagles, as also those relating to the other rapacious birds, will be read with much interest; as will also the details concerning the nesting-habits of many of the rarer species of European birds, several of which, such as the Rough-legged Buzzard and the Lapp Owl, were first tracked to their breeding-quarters in the remotest wilds of Scandinavia by this indefatigable naturalist.[10]