... exterior. Before the advent of civilized man, they attached their nests to the sides of caves, in crevices among rocks and in hollow trees, as they do now in some localities. Their eggs cannot be distinguished from those of the Cliff Swallow. Data.—Penikese Is., Mass., July 2, 1900. Nest on beam in sheep shed; made of pellets of mud, lined ... — The Bird Book • Chester A. Reed Read full book for free!