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PART II. 
GENERAL ORNITHOLOGY: 
AN OUTLINE OF THE f 
STRUCTURE AND CLASSIFICATION OF BIRDS. 
§ 1.— DEFINITION OF BIRDS. 
ENERAL ORNITHOLOGY, like Field Ornithology, is a subject with which the 
student must have some acquaintance, if he would hope to derive either pleasure or 
profit from the Birds of North America. For any intelligent understanding of this subject, he 
must become reasonably familiar with the technical terms used in describing and classifying 
birds, and learn at least enough of the structure of these creatures to appreciate the characters 
upon which all description and classification is based. Extensive and varied and accurate as 
may be his random perception of objects of natural history, his knowledge is not scientific, but 
ouly empirical, until reflection comes to aid observation, and conceptions of the significance of 
what he knows are formed by logical processes in the mind. For 
Science (Lat. scire, to know) is knowledge set in order; knowledge disposed after the 
rational method that best shows, or tends to show best, the true relations of observed facts. 
Sound scientific facts are the natural basis of all philosophic truth, and the safest stepping- 
stones to religious faith, —to that wisdom which comes only of knowing the relation which 
material entities bear to spiritual realities. The orderly knowledge of any particular class of 
facts —the methodical disposition of observations upon any particular set of objects — constitutes 
a Special Science. Thus 
Ornithology (Gr. épuos, ornithos, of a bird; doyos, logos, a discourse) is the Science of 
Birds. Ornithology consists in the rational arrangement and exposition of all that is known of 
birds, and the logical inference of much that is not known. Ornithology treats of the physical 
structure, physiological processes, and mental attributes of birds ; of their habits and manners ; 
of their geographical distribution and geological succession; of their probable ancestry; of 
their every relation to one another and to all other animals, including man, —in short, of their 
* significance in Nature and Supernature. The first business of Ornithology is to define its 
ground — to answer the question, 
