THE VESSELS. 335 



1. Nutritice tibia, large, passes downwards on the posterior and outer side of 

 tibia as far aeforam. nutrit., and supplies the medullary cells. 



2. Art. peroncea s.jibularis. Origin : at an acute angle, one inch to an inch 

 and a half below the origin, on the outer wall oftibial. postica. Course : down- 

 wards along the inner posterior surface of the fibula, separated from it by 

 flexor halluc. long., and behind the external malleolus, on the outer side of 

 calcaneus. Position: covered behind by m. soleus upon tibialis posticus, then 

 between this and flex, halluc. longus, upon lig. interosseum. Behind malleolus 

 externus; on the external border oi'tendo Achillis covered by fascia and skin, 

 only. 



a. Muscular branches backwards for m. soleus, externally for mm. peronasi 

 and a nutritia fibulae [directed downwards] . 



b. Peron&a anterior s.perforans, a thinner branch, passes down on the 

 inferior third of the tibia through the lig. interosseum on its anterior 

 surface, and passes into the rete malleol. externum. 



c. Peron&a posterior, a continuation of art. peroncsa, passes along the 

 outer border of the tendo Achillis, covered by fascia and skin, only, to 

 the outer surface of calcaneus, and anastomoses with art. malleolar. and 

 plantar, externn., and gives a transverse uniting branch which passes 

 between the tendo Achillis and the bones to the tibialis postica. 



3. Malle.olaris interna posterior arises behind the inferior extremity of tibia, 

 passes close to the bone from the tendons of tibialis posticus and flex, digit, 

 long, to the inner malleolus and into rete malleolare internum. 



4. Plantaris interna, the smaller internal terminal branch of art. tibialis 

 postica. Course : along the inner border of the sole of the foot (one inch re- 

 moved from it) forwards. Position: between abductor hallucis (within) and 

 flexores digitor. (without), covered by the fascia plantar. 



Branches: ascending to the articulations of the metatarsal bones. Termi- 

 nal branches from the posterior extremity of os metatarsi hallucis : 



a. Ram. internus, passes along the inner border of the m. abductor hallucis 

 superficially. 



b. Ram. internus, anastomoses with the trunk of art. inteross. plantar. L 

 A branch passes through^asc. plantaris to the skin of the inner side. 



5. Plantaris extcrna, the deeper external terminal branch of tibial. postica. 

 Course : from the inner side otcalcaneus* obliquely outwards and forwards as 

 far as the posterior extremity of os metatarsi V.; an inch distant from the 

 outer border of the foot ; then curved inwards above oss. metatarsi 4 to 2, 

 where it anastomoses with art . pedicea (see arcus plantaris). Position: upon 

 the tendons of flex, digit, commun. and halluc., caro quadrata, flex, digit. 5. 

 brev. and interossei; covered behind by lig. laciniat., then by abduct, halluc., 

 flexor digit, brevis, aponeurosis plantar, (below). 



Branches: to the calcis, to mm. flexor, digit, brev. and caro quadr., to the 

 Tarsus. Art. plantaris digiti V. externa passes under flex, brevis digit. V., 

 terminates at the outer border of the plantar surface of the little toe, and anas- 

 tomoses with art. dortales tarsi (compare Arcus plantaris and Art. tarsea 

 externa.) 



