OSTEOLOGY AND SYNDESMOLOGY. 39 
'4,. Tur Foor is composed of twenty-six bones, which are arranged in 
three parts, the tarsus, metatarsus, and toes. The bones of the tarsus (pl. 
122, figs. 28, 29, 3°; pl. 128, figs. 48 and 49) are seven: astragalus, 
caleaneum, navicular, cuboid, and three cuneiform (internal, middle, and 
external). These are arranged in two rows, the first embracing the astra- 
galus, os calcis, or caleaneum; the second row consists of five bones: the 
cuboid bone forms it externally alone, but on the inner side it presents two 
short transverse rows, the navicular forming the posterior, and the three 
cuneiform bones the anterior. 
The astragalus (pl. 128, fig. 48") comes next to the caleaneum in point 
of size, and is situated at the upper and middle part of the tarsus, where it 
is wedged between the two malleoli ; superiorly it articulates with the tibia, 
inferiorly with the calcaneum, anteriorly with the scaphoid, and externally 
with the fibula. 
The calcaneum or os cdlcis (fig. 49°) is the largest bone in the: tarsus, at 
the lower and posterior part of which it is placed: it is elongated posteriorly 
into a process called the heel; its upper surface presents two articulating 
surfaces, the support of the astragalus; the anterior extremity presents an 
articular surface for the cuboid bone; the posterior extremity is roughened 
below, for the attachment of the tendo Achilhs; the inferior surface presents 
two tubercles, for the attachment of muscles and ligaments: externally it is 
flat, and marked with two shallow grooves, separated by a spine; internally 
it is broad, and hollowed out into an arch, through which pass various 
nerves, vessels, and tendons. 
The navicular or scaphoid bone (fig. 48°) is situated about the middle of 
the tarsus, and at its upper and internal part; of an oval form, its long axis 
directed downwards and forwards: the posterior surface forms a superficial 
glenoid cavity, for the head of the astragalus ; the anterior surface is convex, 
and divided by two vertical ridges into three surfaces, for the three cunei- 
form bones; on the external side there is usually a small flat articular sur- 
face, for the cuboid bone; the scaphoid is connected to the caleaneum by a 
strong ligament. 
The cuboid bone (fig. 48") is situated at the outer and anterior part 
of the tarsus, external to the navicular, and anterior to the calcaneum ; 
it articulates posteriorly with the calcaneum, internally with the scaphoid 
and the external cuneiform, and anteriorly with the fourth and fifth, or the 
two external metatarsal bones. 
The three wedge-shaped cunerform bones (fig. 48* °°) are situated at the 
anterior part of the tarsus, between the scaphoid and the three internal © 
metatarsal bones: the first or internal is the largest, and the middle the 
smallest; the first articulates with the scaphoid, the second metatarsal, and 
the second cuneiform; the second also articulates behind with the scaphoid, 
before with the second metatarsal; the third articulates anteriorly with the 
third metatarsal, posteriorly with the scaphoid, internally with the middle 
cuneiform and with the second metatarsal, and externally with the cuboid 
and with the fourth metatarsal. 
The metatarsus (fig. 48°) consists of five long bones, parallel, and sepa- 
745 
