Much, very much more, might have been said of these wings: but our conversation is of birds. We cannot, however, properly appreciate either the essential characters of their wings, or their flight, without some such standards of comparison as is afforded by the wings of other creatures. [Illustration: A Primaries. B Secondaries. C Tectrices. D Bastard Wing. The upper figure shows the under side of wing with the coverts removed to show attachment of flight feathers to skeleton. The lower figure shows the quill or flight feathers and the coverts in their natural condition.] CHAPTER II The First Bird. "And let Fowl fly above the earth; with wings Displayed in the open firmanent of heaven."--_Milton._ The ancestors of birds--The first known bird and its many remarkable features--The gradual evolution of the birds of to-day. Sooner or later all bird-lovers find themselves pondering over the problem of the origin of birds: how they evolved their peculiar covering of feathers: what was the fashion of the original arm and hand out of which the wing was fashioned: and finally, whence have the birds been derived? Since these pages are avowedly devoted to the subject of Flight, any attempt to summarize the state of our knowledge on these aspects of the history of birds would be in the nature of a trespass on the space, of necessity limited, which even a cursory survey of flight demands. Let it suffice, then, to say, that birds are descended from reptiles. The skeleton of modern birds bears undubitable testimony of this. For we have the evidence furnished us by the remains of two remarkable skeletons, belonging to that very wonderful reptile-like bird, Archæopteryx.