Comparative anatomy of the great horned owl andwhistling swan.

Abstract

The anatomy of birds has been the subject of many monographs and comparative treatises having for their aim the establishment of a classification based on natural or genetic affinity. Nesting habits, modes of progression, skeleton, and muscles have been examined in turn without arriving at a final settlement of the question. There are more species of birds than of mammals, but fewer definable orders. Birds as a whole present a degree of adaptive radiation such as is to be found in a single order of reptiles or of mammals, and this is expressed anatomically in the presence or absence, atrophy or hypertrophy of parts. The information on these matters is scattered and in some instances confused, and practically no anatomical research has been devoted to local Canadian birds. [...