EXTREMITIES. 49 



internal fiirnislied with ligamentous imprints. The os 

 calcis has an external face flat and smooth, an internal 

 face forming the tarsal arc.h, an anterior horder con- 

 cave, a posterior l)order thick and rough, a superior 

 extremity divided in three parts : one middle, for mus- 

 cular attachment ; one anterior, smooth, and one pos- 

 terior for the sliding of a tendon ; an inferior ex- 

 tremity, articular — it is developed by t\vo nuclei of os- 

 sification and the astragalus by onfe"<tTi^y. The inferior 

 row has four bones ;,\the cul^oid with six faces ; the 

 scaphoid, flat bone, with two faces and a circumfer- 

 ence ; the great cuneiform with two articular faces and 

 three borders ; the small cuneiform sometimes divi- 

 ded in two pieces, with four facet tes for articula- 

 lation. Development : all the bones of the inferior 

 row are dev^eloped by one nucleus of ossification . 



Metatarsi. — Similar to the metacarpi. 



Principal Metatarsus is longer, more cylindrical 

 than the metacarpus, and has on the outside border an 

 oblique Assure. Its superior articular surface is hol- 

 lowed by a fossa of insertion. 



Rudimentary Metatarsi. — The external is always 

 the longest and the tliickest ; the internal has three 

 articular facets on the superior extremity. 



Phalanges. — Almost exactly like those of the an- 

 terior extremity. 



