INTEODUCTION. 
SECT. I. OrnirgoLtogy Drerinrp— Birps DEFriInED— BrirF DEscrIPTion 
OF THEIR PECULIAR COVERING. 
§ 1. Scrence (Lat. scire, to know) is knowledge set in order; knowledge 
disposed after the rational method that best shows, or tends to show, the mu- 
tual relations of observed facts. Such orderly knowledge of any particular 
class of facts — such methodical disposition of observations upon any par- 
ticular set of objects — constitutes a Special Science. Thus, OrnrTHOLOGY 
(Gr. ornithos, of a bird, logos, a discourse) is the Science of Birds. Or- 
nithology consists in the rational arrangement and exposition of all that is 
known of birds. Ornithology treats of the physical structure, physiological 
processes, and mental attributes of birds; of their habits and manners; of 
their geographical distribution ; of their relations to each other and to other 
animals. The first business of Ornithology is to define its ground; to 
answer the question 
§ 2. Wuat is A Brrp? A Bird is an air-breathing, egg-laying, warm- 
blooded, feathered vertebrate, with two limbs (legs) for walking or swim- 
ming, two limbs (wings) for flying or swimming, fixed lungs in a cavity 
communicating with other air-cavities, and one outlet of genito-urinary and 
digestive organs ; with (negative characters) no teats, no teeth, no fleshy lips, 
no external fleshy ears, no (perfect) epiglottis nor diaphragm; no bladder, 
no scrotum, no corpus callosum ; and with the following collateral characters, 
mostly shared by more or fewer other animals :— Under jaw hinged with 
_ the rest of the skull by means of an interposed movable bone, that is also 
movably jointed with two bones of the upper jaw; head jointed with neck 
by only one hinge; shoulder-joints connected with each other by a curved 
bone, the clavicle (with rare exceptions), and with breast-bone by a straight 
stout bone, the coracoid; ribs all bony, most of them jointed in the middle 
as well as with back-bone and breast-bone, and having bony offsets; less 
than three separate wrist and hand-bones ; two fingers, of one or two bones ; 
head of thigh-bone hinged in a ring, not in a cup; one of the two leg-bones 
not forming the ankle-joint; no separate ankle-bones; less than three sep- 
arate foot-bones; two to four toes, of two to five bones, always ending in 
claws; both jaws horny-sheathed and nostrils in the upper one; feet and 
toes (when not feathered) horny-sheathed ; three eyelids ; eyeball with hard 
KEY TO N. A. BIRDS. 1. (1) 
