POSTERIOR TIBlAL ARTERY, AND ITS BRANCHES. 247 



ments of the sole of the foot; it then divides into two branches, 

 the Internal and External Plantar Artery. 



The Internal Plantar Artery (Art. Plantaris Interna) is 

 much smaller than the other. It advances between the abduc- 

 tor pollicis pedis and the internal inferior margin of the sole of 

 the foot, arid terminates at the anterior end of the first metatar- 

 sal bone, by joining the internal digital artery of the great toe. 

 In this course, it sends, continually, small ramifications to the 

 muscles of the great toe and to the flexor brevis digitorum pe- 

 dis. One of the largest of these ramifications comes off near the 

 os scaphoides, and cruises along the internal margin of the ab- 

 ductor pollicis to its anterior end; another becomes superficial 

 on the sole of the foot, between the abductor pollicis and the 

 flexor brevis digitorum, and goes forward as far as the other. 



The External Plantar Artery (Art. Plantaris Externa) is 

 the continuation of the posterior tibial, and diverges from the 

 internal plantar towards the outer margin of the sole of the foot, 

 between the flexor brevis digitorum pedis and the flexor acces- 

 sorius. Having reached the internal margin of the abductor 

 minimi digiti, it advances along the latter to the base of the me- 

 tatarsal bone of the fourth toe; it then makes a curvature for- 

 wards and inwards across the metatarsal bones, between the ten- 

 dons of the flexor longus digitorum and the interosseous muscles, 

 to the first metatarsal interval, where it is joined by the an- 

 terior tibial artery from above. This curvature is the Arcus 

 Plantaris, of which the concavity is behind and inwards. 



The external plantar artery is distributed as follows: 



Shortly after its origin, it detaches a branch which goes back- 

 wards and outwards, and which, keeping close to the os calcis 

 in front of its tuberosity, is distributed to the heads of the mus- 

 cles arising from it, and to the outer surface of the heel; it also 

 sends an arteriole along the external edge of the abductor mini- 

 mi digiti. 



At the base of the fourth metatarsal bone, arises a branch 

 called the External Digital Artery of the Little Toe. It goes 

 at first deeply along the internal margin of the muscles situ- 

 ated on the fifth metatarsal bone, and, afterwards, at the head 



