own intelligence in guiding them from place to place; even many migratory species far exceed the bounds of their usual resorts, and certain individuals, not known to be migratory, have found their way across the whole continent of Europe. A good example of the latter is seen in the late irruption of Pallas's sand-grouse from north-western Asia, so well illustrated by Messrs. Moore and Newton, in the "Ibis." The short-toed lark seldom {60} migrates beyond the northern shores of the Mediterranean, yet finds itself often in Britain, and caught either in gales, or wandering unknowingly northward; occasional individuals of the Egyptian vulture from Spain, the Griffon vulture and spotted eagle from the mountains of central Europe, and the spotted cuckoo from north Africa. Moreover, several American species have been recorded, chiefly water birds, which, of course, are better adapted to brave the dangers of the deep. Certain birds--to wit, the redbreast, song-thrush, and black-bird--do not leave the north of Europe, whilst many of their brethren of Italy and the neighboring countries make regular annual migrations to Africa and the islands. To account for this remarkable anomaly, it will be observed that the robin of the south is far less omnivorous than its northern compeer, and is not nearly so familiar in its habits--like the warblers, it depends almost entirely on insect food; consequently, when that fails, it has no alternative but to push southward, and participating, like other species, in climatic effects, it would doubtless follow a like route; and much the same with the thrushes, as they depend in a great measure on fruits for their winter subsistence. When the grapes of the south are gathered, having no holly-berries, mountain ash, or haws to draw on for their winter wants, they would naturally disperse; probably many fly northward as well; for all the thrushes that cross the Mediterranean during winter are but an infinitesimal part of what frequent Italy and the south of Europe in summer. No doubt much depends on the nature of the locality, whether favorable or otherwise; and wherever a complete or only partial failure of food has taken place, so accordingly will the species depart or remain. Moreover, what has just been remarked in connection with the stone-chat, might be applied again to the robins and thrushes of southern Europe: supposing one of either hatched in Italy, and after several years' migrations to the oasis of the desert, should deviate on one occasion from its accustomed course and fly northward, and spend the winter in northern Europe,--with the example of the resident individuals before it, no doubt the robin would soon pick up crumbs at the kitchen door, and the thrushes crowd with their indigenous brethren on the holly-trees, and, becoming climatized, remain in their adopted countries ever afterward. Although we have no direct proof that such occurrences actually take place, there is nothing in the bird's