770 MAMMALIAN ANATOMY 



bones and a rudimentary ossicle, called metatarsals, which are placed 

 side by side, united at their proximal ends where they articulate with 

 the tarsal bones, and distally free and diverging to support the digits. 



The metatarsus as a whole is a flattened oblong, whereof the middle 

 length is three times as great as the width at the proximal end, and 

 twice as great as the width at the distal end. The outline of its 

 proximal extremity is irregular, owing to the different shapes and 

 lengths of the bases of the metatarsal bones. The sides are bowed 

 toward the middle line, the outer or fibular side more strongly than 

 the inner or tibial. The outline of the distal extremity is that of a 

 truncated triangle, owing to the fact that the two median metatarsals 

 are longer than the two lateral. The dorsal aspect of the metatarsus 

 is gently convex from the proximal to the distal end and strongly 

 convex from side to side ; the plantar surface is, therefore, correspond- 

 ingly concave in these directions. 



The metatarsus is a fourth longer than the tarsus and a little more 

 than a fourth longer than the middle digit. Its width at the proximal 

 end is about the same as the width of the tarsus ; at the distal end it 

 is somewhat wider. It differs from the metacarpus in having but four 

 large constituent bones, which are placed more closely together, and in 

 being about a third longer and slightly wider. 



Nomenclature. The word metatarsus was not known to the 

 Greeks nor used by Galen. It was introduced by Laurentius, and is 

 a compound of meta, beyond, and tarsus. The German for metatarsus 

 is der Mittelfuss ; the French, le metatarse. 



CHARACTERS COMMON TO ALL METATARSAL BONES. 



General Description. The Metatarsals so closely resemble the 

 metacarpals that, except for the difference in size, they can be distin- 

 guished from them only by minor characters. They have irregular 

 bases ; long, slightly curved shafts, presenting tibial, fibular, and 

 plantar borders, dividing dorsal, tibial, and fibular surfaces, and 

 rounded, keeled heads. The base of each metatarsal is so very similar 

 to the base of the corresponding metacarpal that the description of 

 the latter already given would almost suffice. For greater clearness 

 a few words concerning the bases may be added. 



Nomenclature. The metatarsal bones are called ossa metatar- 

 salia, and are numbered from the tibial to the fibular side, namely, 



