68 HUMAN ANATOMY. 



It is developed from three ossific centres, one each for shaft, 

 head, and malleolus. 



THE FOOT. 



The bones of the foot consist of seven tarsus., five metatarsus, 

 and fourteen phalanges. 



THE TAKSAL BONES are calcaneum, astragalus, cuboid, sca- 

 phoid, and internal, middle, and external cuneiform. 



They may be arranged into two series, anterior and posterior, 

 the calcis and astragalus behind, and all the others in front of 

 the calcaneo-cuboid, astragalo-scaphoid joint [Chopart's]. 



CALCANEUM, or os calcis, the largest, is irregularly cuboidal. 



The superior surface presents two articular surfaces for the 

 astragalus, separated by a groove for the calcaneo-astragaloid 

 ligament, and internally a projecting process, the sustentacu/nin 

 tali, for calcaneo-cuboid ligament. The inferior surface, rough 

 and excavated, presents two tubercles, an outer and inner tubercle, 

 for muscles and ligaments. 



Internal surface is concave, for passage of flexor longus, and 

 tibialis posticus tendons, and plantar vessels and nerves. 



External surface presents tubercle for external lateral liga- 

 ment of ankle and grooves for peroneal tendons. 



Posterior surface, projecting behind, presents a smooth sur- 

 face above for bursa and rough below for attachment of tendo 

 Achillis. 



It articulates with astragalus and cuboid. 



Muscular attachments are eight tendo Achillis, plantaris, 

 tibialis posticus, abductor pollicis and minimi digiti, flexor 

 brevis, digitorum and accessorius, extensor brevis digitorum. 



ASTRAGALUS is an irregular, short bone, consisting of body, 

 neck, and head. The quadrilateral body presents four articular 

 surfaces, above for lower extremity of tibia and internal mal- 

 leolus and external malleolus; below two surfaces for os cah-is, 

 separated by deep groove for interosseous calcaneo-astragaloid 

 ligament; posteriorly it presents a deep groove for flexor longus 

 pollicis tendon; and anteriorly, the rounded convex head sup- 

 ported on neck articulates with scaphoid, and rests upon calcaneo- 

 scaphoid ligament. 



It articulates with four bones tibia, fibula, scaphoid, and 

 os calcis. It has no muscular attachments. 



CUBOID (cube-like) is a small, pyramidal bone, between the 

 os calcis and the fourth and fifth metatarsal bones on the outer 

 side of the foot. 



The upper or dorsal surface is rough for ligamentous attach- 

 ment; the lower or plantar surface is grooved for tendon of pero- 



