When the nesting-time comes around, the last of April or the beginning of May, these birds are not so engrossed with the thoughts of feeding as to be utterly oblivious of the duties which it imposes. Generally the same nest is selected year after year, but when a new one is to be constructed it is not uncommon to find many pairs engaged in its building, the friends of the destitute assembling and laboring with the most determined energy till its completion. A more sociable disposition could hardly be conceived. The spirit which would lead these birds to fly to the assistance of a distressed companion would certainly induce them to co-operate with their brethren in the difficult task of nest-building, especially when such a bulky structure as the species is known to construct would severely task both the time and patience of the pair which is to occupy it. The vast amount of labor and time expended in rearing such a fabric is a sufficient inducement for them not to want to indulge in such employment any more than is absolutely necessary. Hence these nests are constructed for durability. Unlike his European congener, whose nest is placed upon a high cliff, the Osprey almost invariably builds on trees. All nests taken by the writer have seldom been at a greater elevation than fifteen feet, although instances have been recorded where they were twice that height. It is a remarkable fact that the trees supporting these nests are always dead and generally placed in the midst of marshy ground, either completely isolated or surrounded by a dense growth of bushes. At all events, they occupy rather conspicuous positions. It is probable that the excrement of the birds or the saline character of their food has much to do with killing the nesting-trees. Trees which seem vigorous and thrifty at first manifest after a year’s occupancy unmistakable signs of death. Not always are trees selected for nesting purposes, for a Mr. W. H. Edwards describes a nest built on a tall cliff on the banks of the Hudson River, not very far from West Point. Externally the nest is composed of large sticks piled to a height varying from two to five feet, and measuring fully three feet in diameter. Corn-stalks, mullein-stocks and bark are occasionally intermingled with the sticks, but within there is a rather profuse lining of sea-weed and the long grasses which grow so luxuriantly in salt-water marshes. The cavity ranges from fourteen to fifteen inches in diameter, and is unusually shallow in proportion to the size of the nest.