30 ANTHROPOLOGY. 
The forearm (pl. 122, fig. 8, D) is composed of the ulna and radius. 
Of these, the ulna or cubitus (figs. 8°, 15") is situated at the inner side 
of the forearm, forming the principal part of the elbow ; it does not directly 
enter into the wrist joint, but falls a little short of it below; it is divided 
into the body and two extremities. The upper extremity is the larger, and 
presents two processes and an intervening cavity. The posterior process, 
or the olecranon (figs. 16, 17, and 18), is the highest part of the bone: 
posteriorly it is smooth; anteriorly it is also smooth, and covered with car- 
tilage. The coronoid process (fig. 17°) is anterior and inferior to the 
-preceding. Externally it is hollowed out into the lesser sigmoid cavity 
(jig. 17°) which receives the head of the radius; superiorly it leads into 
the great sigmotd cavity (fig. 16’) which moves on the trochlea of the 
humerus in flexion and extension of the forearm; the profile of this cavity 
resembles the letter C. The lower or carpal end (fig. 21”) is small and 
round, with two eminences. ‘The external is named the head; it is round, 
and covered with cartilage, and received into the cavity in the inner border 
of the radius. The internal eminence, or styloid process (fig. 21”), is more 
prominent, and on a level with the posterior surface of the bone. The ulna 
articulates above with the humerus and radius, and below with the radius 
and interarticular cartilage. 
The radius (figs. 3°, 15°) is shorter than the ulna, and, while only 
accessory as a rotating bone in the elbow, it is the pina bone in the 
carpal joint. It is divided into the body and two extremities. The upper 
or humeral end presents a head, neck, and tubercle. The head (jig. 19”) 
is a circular superficial cavity, with the surface and circumference covered 
with cartilage, the former to articulate with the small head of the humerus, 
the latter with the sigmoid cavity of the ulna and with the annular ligament. 
The neck (jig. 19”) is nearly an inch long, descends obliquely inwards, and 
is contracted and circular. At its lower extremity, where it joins the shaft, 
is the tubercle (fig. 19°). The body or shaft is somewhat triangular, and pre- 
sents three surfaces, separated by three margins or angles. The lower or 
carpal end of the radius is irregularly square; its anterior prominent edge 
gives attachment to the anterior carpal ligament. Posteriorly there are 
seen three grooves: one nearly in the middle line, the second at the ulnar 
side of this, and the third on the radial side. The styloid process is the 
inferior extremity of the radius; from its point arises the external lateral 
ligament of the wrist. 
The hand (pl. 122, fig. 3 £; pl. 128, figs. 46 and 47) consists of the carpus, 
-metacarpus, and phalanges; twenty-seven bones in all. 
_ The carpus is composed of eight bones, arranged in two rows: the first 
row consists of the scaphoid, lunar, cuneiform, and pisiform; the second of 
the trapezium, trapezoid, magnum, and unciforme; enumerating them from 
the radial to the ulnar side, or from without inwards. 
The scaphoides or navicular bone (pl. 123, fig. 47°). This is the largest 
in the upper row, and is situated at its outer or radial side. It presents four 
articular surfaces, by which it articulates with the radius, the trapezium, the 
trapezoid, the lunar, and the magnum. The lwnare or semicircular bone 
78 
