158 



GENERA L ORNITHOL G Y 



Of?iy^ 



aspect in the bird. The humerus is a cylindric bone, straightish or 

 somewhat italic-/-shaped, "svith a globular head to fit the socket of 

 the shoulder, a strong pectoral ridge for insertion of the breast 

 muscles, and at the bottom two condyles (Fig. 28, re, ue) or joint- 

 surfaces for articulation Avith a pair 

 of succeeding bones. The forearm, 

 cuhit or antehraehium, extending from 

 elboAv to wrist, B to C, in Fig. 27, 

 has two parallel bones of about 

 equal lengths. These are the ulna, 

 III, and the radius, rd ; the former, 

 inner and posterior, the larger of 

 the two, bearing the quills of the 

 secondary series ; the latter, slen- 

 derer, outer, and anterior. The 

 enlarged proximal extremity of the 

 ulna is called the olecranon, or, 

 "head of the elbow." The third 

 segment of the wing is the wrist or 

 carpus. In adult life, this normally 

 consists of two little knobby carpal 

 bones, extremely irregular in shape, 

 called the scapliohmare, sc, and cunei- 

 fonne, cu. One being at the end of 

 the radius, the other at that of the 

 ulna, they are also called radiale 

 Fig. 29, from a young cock-of-the-piains ^nd uliiare. In the embryo there 



(Ceyitrocercus urophasianus, six months old) jg at least One Other carpal boue, 



is designed to show the composition of tlie . ^ r • i i 



carpus and metacarpus before the elements that early tuses AVlth the next 



of these bones fuse together: r, radius: w, j. j • i,* i j.i 



ulna ; s, scaphoiunar or radiale ; c, cunei- Segment, and in many birds there 



form or ulnare ; om a carpal bone believed g^^g several SUch. This fourth Seg- 



to be OS magnum, later fusing with the . '^ 



metacarpus ; z, a carpal bone, supposed to ment is the liana proper, or metaj- 



be unciform, later fusing with metacarpus ; /-< , n / i • p ? 



- - - - - -■ ■ carpus, me, C to A (exclusive oi d 



9^ 



The single metacarpal or hand- 

 bone is very composite ; that is, 

 compounded of several ; for, besides 

 including certain carpal elements, 

 as already said, it consists of three 



8, an unidentified fifth carpal bone, which 

 may be called pcntosteon, later fusing with 

 the metacarpus ; 7, radial or outer meta- 

 carpal bone, bearing the pollex or outer 

 digit, consisting of two phalanges, d and k ; 

 9', principal (median) metacarpal bone, 

 bearing the middle finger, consisting of the 

 two phalanges, d', d" ; 9, inner or ulnar 

 metacarpal, bearing a digit of one phalanx, 

 d'". The pieces marked om, z, 7, S, 9, all '" J -— .-, _- -- -_ __ 



fuse with 9' to form the single compound bones fused (in all recent birds) in 



metacarpal bone marked mc. in Fig. 27. ,. ^ .-, .,' 



(From nature, by Dr. R. w. siiufeidt, oue, Corresponding to the three 

 ^•^•^•) digits or fingers that birds possess. 



In fact it is three metacarpals in one. The metacarpal corre- 

 sponding to the principal finger is much the largest of the 

 three ; that of the first finger is very short, being only the 

 expanded part seen in the figure, just above the bone marked 



