TEE POSTERIOR LIMBS. 



147 



tendon of the perforatus. The inferior extremity, wide and voluminous, shows in 

 front three or four articular facets which articulate with the astragalus, and are 

 (Separated, like those of the last bone, by an irregular and slightly excavated sur- 

 face for insertion. Below, it shows for articulation with the cuboid a fifth facet, 

 continuous with one of the preceding. 



Developynent. — The calcaneum is developed from two nuclei of ossification, 

 one of which is for the summit. 



Cuboid hone (Figs. 98, 99). — This little bone, situated at the external side of the 

 scaphoid and the large cuneiform bone, between the calcis and two of the metatar- 

 sals, does not resemble a cube, but a parellelopiped elongated from before to behind. 

 It offers six faces : a superior, an articular face, in contact with the calcaneum ; 

 an inferior, also articular, articulating with the principal and external rudimen- 

 tary metatarsal hones ; an internal, furnished with three facets for contact with 

 the scaphoid and great cuneiform, and crossed from before to behind by a fissure, 



Fig. 100. 



Fig. 101. 



LEFT HOCK (FRONT VIEW). 



1, Apex of calcaneum ; 2, astragalus, inner 

 ridge ; 3, cuneiform magnum ; cunei- 

 form medium ; 5, cuboid. 



LEFT HOCK (INTERNAL ASPECT). 



1, Apex of calcaneum ; 2, inner articular 

 ride of astragalus ; 3, navicular, scaphoid, 

 or cuneiform medium ; 4, cuneiform mag- 

 num ; 5, cuboid ; 6, cuneiform parvum. 



which forms with these two bones a vascular canal ; an external, an anterior, and 

 B> posterior, covered with imprints. 



Scaphoid hone (the large cuneiform of Percivall) (Figs. 98, 99). — Flattened above 

 and below, it is described as having two faces and a circumference. The faces, both 

 articular, are furrowed by a channel of insertion, and are distinguished as superior 

 and inferior. The first is concave, and articulates with the astragalus ; the second 

 is convex, and in contact with the two cuneiform bones. The circumference offers, 

 outwardly, two small facets, which are adapted to similar facets on the cuboid 

 bone. For the remainder of its extent, it is covered with imprints (Fig. 99). 



Oreat Cuneiform hone (the middle cuneiform of Percivall) (Figs. 99, 100, 101). — 

 Flattened above and below, and triangular in shape, this bone is much smaller than 

 the scaphoid, though resembling it in a striking manner. Its superior face is in 

 contact with the latter bone, and its inferior face articulates with the middle and 

 internal lateral metatarsal bones. Its external harder is provided with one or two 

 facets to correspond with the cuboid bone ; and its internal herder also shows one. 



