H6 OSTEOLOGY. 



in front. It may be distinguished by its large size, as compared with the other 

 two, and from its more irregular wedge-like form. It presents for examination 

 six surfaces. 



The internal surface is subcutaneous, and forms part of the inner border of the 

 foot. It is broad, quadrilateral, and presents at its anterior inferior angle a smooth 

 oval facet, over which the tendon of the Tibialis anticus muscle glides ; rough in 

 the rest of its extent, for the attachment of ligaments. The external surface is 

 concave, presenting, along its superior and posterior borders, a narrow surface for 

 articulation with the middle cuneiform behind, and second metatarsal bone in 

 front ; in the rest of its extent, it is rough for the attachment of ligaments, and 

 prominent below, where it forms part of the tuberosity. The anterior surface, 

 reniform in shape, articulates with the metatarsal bone of the great toe. The 

 posterior surface is triangular, concave, and articulates with the innermost and 

 largest of the three facets on the anterior surface of the scaphoid. The inferior 

 or plantar surface is rough, and presents a prominent tuberosity. at its back part 

 for the attachment of part of the tendon of the Tibialis posticus. It also gives 

 attachment in front to part of the tendon of the Tibialis anticus. The superior 

 surface is the narrow pointed end of the wedge, which is directed upwards and 

 outwards ; it is rough for the attachment of ligaments. 



To ascertain to which side it belongs, hold the bone so that its superior narrow 

 edge looks upwards, and the long articular surface forwards ; the external surface 

 marked by its vertical and horizontal articular facets will point to the side to 

 which it belongs. 



Articulations. "With four 'bones: scaphoid, middle cuneiform, and first and 

 second metatarsal bones. 



Attachment of Muscles. The Tibialis auticus and Tibialis posticus. 



THE MIDDLE CUNEIFOEM. 



The Middle Cuneiform, the smallest of the three, is of very regular wedge- 

 like form ; the broad extremity being placed upwards, the narrow end downwards. 

 It is situated between the other two bones of the same name, and corresponds to 

 the scaphoid behind, and the second metatarsal in front. 



The anterior surface, triangular in form, and narrower than the posterior, arti- 

 culates with the base of the second metatarsal bone. The posterior surface, also 

 triangular, articulates with the scaphoid. The internal surface presents an articular 

 facet, running along the superior and posterior borders, for articulation with the 

 internal cuneiform, and is rough below for the attachment of ligaments. The 

 external surface presents posteriorly a smooth facet for articulation with the 

 external cuneiform bone. The superior surface forms the base of the wedge ; it 

 is quadrilateral, broader behind than in front, and rough for the attachment of 

 ligaments. The inferior surface, pointed and tubercular, is also rough for liga- 

 mentous attachment. 



To ascertain to which foot the bone belongs, hold its superior or dorsal surface 

 upwards, the broadest edge being towards the holder, and the smooth facet, limited 

 to the posterior border, will point to the side to which it belongs. 



Articulations. With four bones : scaphoid, internal and external cuneiform, and 

 second metatarsal bone. 



THE EXTERNAL CUNEIFORM. 



The External Cuneiform, intermediate in size between the two preceding, is of 

 a very regular wedge-like form, the broad extremity being placed upwards, the 

 narrow end downwards. It occupies the centre of the front row of the tarsus 

 between the middle cuneiform internally, the cuboid externally, the scaphoid 

 behind, and the third metatarsal in front. 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 



