256 THE SKELETON. 



internal cuneiform bone by its more regular wedge-like shape, and by the 

 absence of the kidney-shaped articular surface : from the middle cuneiform, by 

 the absence of the bent, or angular, facet, and by the two articular facets which 

 mark both its inner and outer surfaces. It has six surfaces for examination. 



The anterior surface, triangular in form, articulates with the third metatarsal 

 bone. The posterior surface articulates with the most external facet of the 

 scaphoid, and is rough below for the attachment of ligamentous fibres. The 

 internal surface presents two articular facets separated by a rough depression ; 

 the anterior one, situated at the superior angle of the bone, articulates with the 

 outer side of the base of the second metatarsal bone ; the posterior one skirts 

 the posterior border, and articulates with the middle cuneiform ; the rough de- 

 pression between the two gives attachment to an interosseous ligament. The 

 external surface also presents two articular facets, separated by a rough non- 

 articular surface ; the anterior facet, situated at the superior angle of the bone, 

 is small, and articulates with the inner side of the base of the fourth meta- 

 tarsal ; the posterior, and larger one, articulates with the cuboid ; the rough 

 non-articular surface serves for the attachment of an interosseous ligament. 

 The three facets for articulation with the three metatarsal bones are continuous 

 with one another, and covered by a prolongation of the same cartilage ; the 

 facets for articulation with the middle cuneiform and scaphoid are also continu- 

 ous, but that for articulation with the cuboid is usually separate. The superior 

 or dorsal surface, of an oblong form, is rough for the attachment of ligaments. 

 The inferior or plantar surface is an obtuse rounded margin, and serves for the 

 attachment of part of the tendon of the Tibialis Posticus, part of the Flexor 

 Brevis Pollicis, and ligaments. 



To ascertain to which side it belongs, hold the bone with the broad dorsal 

 surface upwards, the prolonged edge backwards ; the separate articular facet 

 for the cuboid will point to the proper side. 



Articulations. With six bones: the scaphoid, middle cuneiform, cuboid, and 

 second, third, and fourth metatarsal bones. 



Attachment of Muscles. Part of Tibialis Posticus, and Flexor Brevis Pollicis. 



THE METATAKSUS. 



The Metatarsal Bones are five in number ; they are long bones, and sub- 

 divided into a shaft and two extremities. 



Common Characters. The Shaft is prismoid in form, tapers gradually from the 

 tarsal to the phalangeal extremity, and is slightly curved longitudinally, so as 

 to be concave fyelow, slightly convex above. The Posterior Extremity, or Base, 

 is wedge-shaped, articulating by its terminal surface with the tarsal bones, and 

 by its lateral surfaces with the contiguous bones ; its dorsal and plantar sur- 

 faces being rough for the attachment of ligaments. The Anterior Extremity, or 

 Head, presents a terminal rounded articular surface, oblong from above down- 

 wards, and extending further backwards, below than above. Its sides are flat- 

 tened, and present a depression, surmounted by a tubercle, for ligamentous 

 attachment. Its under surface is grooved in the middle line, for the passage of 

 the flexor tendon, and marked on each side by an articular eminence continu- 

 ous with the terminal articular surface. 



Peculiar Characters. The First is remarkable for its great size, but is the 

 shortest of all the metatarsal bones. The shaft is strong, and of well-marked 

 prismoid form. The posterior extremity presents no lateral articular facets ; its 

 terminal articular surface is of large size, of semilunar form, and its circum- 

 ference grooved for the tarso-metatarsal ligaments ; its inferior angle presents 

 a rough oval prominence for the insertion of the tendon of the Peroneus 

 Longus. The head is of large size ; on its plantar surface are two grooved 

 facets, over which glide sesamoid bones ; the facets are separated by a smooth 

 elevated ridge. 



