120 GENERAL OBNITHOLOGY. 



such cases, the feather-border of the wing pronounces the letter W quite strongly, — outer 

 lower angle at point of primaiies ; middle upper angle at reentrance between primaries and 

 secondaries ; inner lower angle at point of tertiaries. 



The "point of the wing" is at the tip of the longest primary. It is best exjjressed when 

 the first primary is longest. Sometimes the end is so much rounded off, that the midmost 

 primary may be the longest one, the others being graduated on both sides of this projecting 

 point. In speaking of the relative lengths of remiges, we always mean the way in which their 

 tips fall together, not the actual total lengths of the feathers. Thus a second primary, whose 

 tip falls opposite the tip of the first one, is said to be of equal length, though it may actually 

 be longer, being seated higher up on the pinion. The development of the primaries also 

 furnishes one of the most important measurements of birds: for the expression "length of 

 wing," or simply "the wing," means the distance from the "bend of the wing," or carpal 

 angle, to the end of the longest primary. The integument of the wing does not very often 

 develop anything but feathers. Occasionally 



Claws and Spurs are found upon the pinion. Claws have been aheady noticed (p. 114). 

 They are properly so caUed, being horny growths comparable in every way to those upon tlie 

 ends of the toes, like the claws of beasts, or human nails. A spur (Lat. calcar), however, is 

 something different, though of the same homy texture, since it does not terminate a digital 

 phalanx, but is ofl*-set from the side of the hand. It is exactly like the spur on the leg of a 

 fowl, which obviously is not a claw. The spur- winged goose {Plectwjyieriis), pigeon (Bidun- 

 culus), plovers (Chettusia, etc.), and the doubly-spurred screamer {Palamedea), afford exam- 

 ples of such outgrowths, of which the Jacauas (Parra) furnish the only, though a very 

 well-marked, illustration among North American bii'ds. (See fig. 53 ter.) 



III. THE TAIL. 



Its Bony Basis. — Time was when birds fiew about with long, lizard-like, bony and 

 fleshy tails, having the feathers inserted in a row on either side like the hairs of a squirrel's. 

 But we have changed all that distichous arrangement since when the Archceoptenjx was 

 steered with such a rudder through the scenes of its Jurassic life. Now the true separate 

 coccygeal bones are few, generally about nine in number, and so short and stimted that they do 

 not project beyond the general plumage, — in fact scarcely beyond the border of the pelvis. 

 Anteriorly, within the bony basin of the pelvis, there are several vertebrae, which, fusing 

 together and with the true sacrum, are termed urosacral or false tail-bones. To these 

 succeed the true caudal vertebrae, movable upon each other and upon the urosacrum. The 

 last one of these, abruptly larger than the rest, and of peculiar shape, bears all the large 

 tail-feathers, which radiate from it like the blades of a fan. The true caudal vertebrae col- 

 lectively fonn the coccyx (Gr. kokkv^, kokkux, a cuckoo; from fancied resemblance of the 

 human tail-bones to a cuckoo's bill) ; the enlarged terminal one is the vomer (Lat. VQmer, a 

 plough-share, from its shape ; not to be confused with a bone of the skull of same name) or 

 l)ygostyle (Gr. Trvyr], inige, rump, and ariikos, stulos, a stake, pale). The pygostyle, however, 

 is a compound bone, consisting of several stunted coccygeal vertebrae fused in one. The bones 

 are moved by appropriate muscles, and upon the surface is seated the elaeodochon (p. 89). The 

 whole bony and muscular affair is famihar to every one as the " pope's nose" of the Christmas 

 turkey; it is a bird's real tail, of which the feathers are merely appendages. In descriptive 

 ornithology, however, the anatomical parts are ignored, the word "tail" having reference solely 

 to the feathers. These, like those of the wings, are of two sorts : the coverts or tcctrices, and 

 the rudders or rectrices (Lat. rectrix, pi. rectrices, a ruler, guider; because they seem tO' 

 steer the bird's thght) ; corresponding exactly to the coverts and remiges of the wings. The 



