THE STRUCTURE AND GENERAL CHARACTER OF PIGEONS. 5 



the position of the different feathers of the wings with regard to the joints of its 

 framework. Into that part of the wing formed of the bones of the hand, d to /, 

 are inserted the flight-feathers of the fancier, the primaries of the naturalist. 

 These are ten in number, the second being usually the longest, and the length 

 diminishing regularly from it to the tenth. In some of the more artificial varieties, 

 as the Short-faced Tumblers, the number of primaries is diminished to nine. 



The secondaries are twelve in number, and take their rise from that part of the 

 wing, c to d, which corresponds to our fore-arm. In some birds a third set of 

 quill feathers, termed tertiaries, take their rise from the humerus b c, but these 

 are not conspicuous in the pigeons. In describing the feathers of the wing, the 

 bastard or spurious pinion e, attached to the rudimentary fore-finger g, must not 

 be overlooked. 



It is impossible to conceive any mechanical contrivance working more smoothly 

 and effectively than the wing of a pigeon. When open each quill feather is sup- 

 ported by, and in its turn supports, those adjacent to it; and thus is formed a 

 concave under surface to strike the air in flight. In closing, each feather glides 

 smoothly over its fellows, and the whole wing shuts up in the smallest possible 

 compass, the primaries passing under the secondaries, so that only their ends are 

 exposed. In flight, the bird raises the extended wing, and then strikes it against 

 the air below with great force. The support of the bird in the air is due to the 

 circumstance that the downward stroke is made with much greater force than 

 that with which the wing is raised, and also to the form of the wing and the 

 curvature of the feathers. The mode in which the forward flight of the bird is secured 

 has been more correctly described by the Duke of Argyll, in his " Reign of Law," 

 than by any other writer. His Grace writes : — 



" The power of forward motion is given to birds, first by the direction in which 

 the whole wing-feathers are set, and next by the structure given to each feather in 

 itself. The wing-feathers are all set backwards, that is, in the direction opposite 

 to that in which the bird moves, whilst each feather is at the same time so con- 

 structed as to be strong and rigid towards its base, and extremely flexible and 

 elastic towards its end. On the other hand the front of the wing, along the 

 greater part of its length, is a stiff hard edge, wholly unelastic and unyielding 

 to the air. The anterior and posterior webs of each feather are adjusted on the 

 same principle. The consequence of this disposition of the parts as a whole, and 

 of this construction of each of the parts, is, that the air which is struck and 

 compressed in the hollow of the wing, being unable to escape through the wing, 

 owing to the closing upwards of the feathers against each other, and being also 

 unable to escape forwards, owing to the rigidity of the bones and of the quills in 

 this direction, finds its easiest escape bachvards. In passing backwards it lifts 

 by its force the elastic ends of the feathers ; and thus, whilst effecting this escape, 

 in obedience to the law of action and reaction, it communicates, in its passage 

 along the whole line of both wings, a corresponding push forwards to the body of 

 the bird. By this elaborate mechanical contrivance the same volume of air is 



