OSTEOLOGY 47 



the scapho-lunar the radius is provided with a terminal transverse 

 convexity produced palmad, which also articulates with the ulna 

 laterally. There is a tuberosity on the radial side of the expansion 

 and inferiorly the inferior tuberculum ossis carpi radialis and supe- 

 riorly a superior tuberculum ossis carpi radialis. 



The Hand. — The hand is made up of the carpus, the metacarpus, 

 and the phalanges. 



The bones of the hand are so arranged as to allow abduction and 

 adduction, or flexion in the ulno-radial plane, movements which are 

 necessary in the outspreading and folding of the wing. Thus the 

 hand of the fowl moves in a state of pronation, without the power of 

 rotation. The carpal bones are so placed between the anterior arm 

 and metacarpus as to reduce the abduction which is necessary to 

 hold and extend the wing, so that the hand or wing be in a fixed 

 position. 



The Carpus. — The carpus in the domestic fowl is represented by 

 two bones, ossa carpi, called the scapho-lunar, or as carpi radiate, 

 and the cuneiform, or os carpi ulnare. The scapho-lunar is the ■ 

 smaller and is located between the' radius and metacarpus. The 

 cuneiform is the larger and is located between the ulna, the radius, 

 and the metacarpus. The cuneiform is somewhat anvil-like in 

 shape, being provided with a body and two prongs. 



The Metacarpus. — The metacarpal bones, or ossa metacarpi, 

 two in number, are separated at liieir middle portion, and consoh- 

 dated at their extremities. The upper proximal base of the meta- 

 carpus is provided with a tubercle, the tuberculum muscularis, and 

 externally the tuberculum ulnare ossis metacarpi. The distal end 

 of the metacarpal bone is provided with a tuberculum articulare. 



The Phalanges. — The first three fingers only are represented, and 

 these are rudimentary. 



The first finger called the poUex or thumb, consists of but one 

 joint. It is located on the proximal and outer end of the metacarpal 

 bone. It has on its proximal end a tubercle, the tuberculum 

 articulare. 



The second finger, the best developed, consists of two phalanxes. 

 These are the main bones extending from the metacarpus. Each 

 articular end is provided with a tuberculum articulare. 



The third finger, small, cylindrical in shape, is located at the 

 distal and inner side of the metacarpal bone. 



