PELVIC LIMBS 771 



from the first metatarsal, or os metatarsale primum, to the fifth meta- 

 tarsal, or os metatarsale quintum. In German they are numbered from 

 der erste to der funfte Mittelfussknochen ; in French, from le premier 

 to le cinquieme metatarsien. 



Articulations. By the base : The first metatarsal articulates with 

 the second metatarsal and the entocuneiform ; the second, with the first 

 and third metatarsals and the three cuneiforms ; the third, with the 

 second and fourth metatarsals and the ectocuneiform ; the fourth, with 

 the third and fifth metatarsals and the cuboid ; the fifth, with the 

 fourth metatarsal and the cuboid. By the head : Every metatarsal 

 articulates with the proximal phalanx of its respective digit. 



Blood -Supply. The nutrient foramen of the second metatarsal 

 is on the fibular border of the shaft, not far from the base ; the fora- 

 mina of the other metatarsals are at the same level, but on the tibial 

 border. The vessels are derived from a common trunk arising from 

 the plantar artery just as it makes its appearance on the sole of the 

 foot, between the second and third metatarsals. 



Ossification. The metatarsals arise by two centres of ossification, 

 one for the base and shaft and one for the head. 



THE FIRST METATARSAL BONE. 



The First Metatarsal (Fig. 587), that of the rudimentary great toe, 

 or hallux, is little more than a bony ossicle applied to the inner and 

 plantar side of the proximal end of the metatarsus. It has a conical 

 shape, although it is subject to much variation in form. On its proxi- 

 mal end is an oval, flat surface for articulation with the entocuneiform. 

 It is firmly united by its roughened fibular side to the tibial side of the 

 end of the second metacarpal. The first metatarsal affords insertion 

 to the tibialis anticus and the peroneus longus, and origin to the first 

 plantar and first dorsal interosseous muscles. 



THE SECOND METATARSAL BONE. 



General Description. The base is bent to the fibular side, but 

 there is no oblique arterial furrow on the dorsal surface (Fig. 588). 



The tibial surface (Fig. 589) presents along the proximal edge a 

 narrow facet for articulation with the distal part of the fibular surface 

 of the entocuneiform. Below this facet is a deep, roughened, oval 

 depression facing principally to the plantar side, and serving for the 



