Ornithology
in natural science, the methodical study, and consequent knowledge of birds, with all that relates to them. It embraces caliology (which treats of nests), oölogy, pterylology, and ornithotomy. Its earliest literature dates from Aristotle (384-322 B. c.), and every succeeding age has added its quota. supported and educated at the public expense. In the Middle Ages such asylums were numerous and generally under the direction of the clergy. In recent times public orphanages have been substituted or supplemented by the farming out system, that is, the children are brought up in private families willing to undertake their charge. Orphan asylums, as conducted in the United States, are supported as private institutions, assisted by legislative appropriation. They are fostered also by the religious denominations.