TEE POSTERIOIi 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. 



Development. — 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 cimeiform bone, between the calcis and two of the metatar- 

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

 It o^ers six faces .- a superior, an articular face, in contact with the calcaneum ; 

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

 tary metatarsal bones ; 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). LEFT HOCK (INTERNAL ASPECT). 



1, Apex of calcaneum ; 2, astragalus, inner i, Apex of calcaneum ; 2. inner articular 



ridge; 3, cuneiform magnum ; cunei- ride of astragalus; 3, navicular, scaphoid, 



form medium ; 5, cuboid. 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 

 2k 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 /aces, both 

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

 and inferio'r. The first is concave, and articulates with the astragalus ; the second 

 is convex, and in contact with the two cuneiform bones. The circumfefi'ence 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). 



Greed Cuneiform hone (the middle cimeiform 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 horder is provided with one or two 

 facets to correspond with the cuboid bone ; and its intei-nal horder ako shows one, 



