The lower part of the peroneal artery may be exposed by an incision commencing at the mid-point between the tendo Achillis and external malleolus, and extending about four inches upwards and outwards towards the fibula. The fibres of the flexor pollicis longus thus exposed, may be detached from the fibula as far as necessary, and the muscle drawn inwards; the vessel will then be observed lying on the interosseous ligament close to the fibula. In order to reach this vessel Mr. Hey recommended sawing out a portion of the fibula.

In a case of a gunshot wound, Mr. Guthrie secured it about four inches below the head of the fibula, by an incision six inches long through the gastrocnemius and soleus muscles.*

Corresponding to the interval between the two origins of the abductor pollicis muscle, the posterior tibial artery terminates by dividing into the internal and external plantar arteries. Immediately before this final division the posterior tibial artery gives off three or four small branches called the internal calcanean, which supply the inner part of the os calcis and the muscles arising from it, together with the areolar tissue and integuments covering the parts in this situation.

Fig. 68. Represents the Arteries of the Internal part of the Foot in an adult.

1, The Soleus Muscle. 2. Tendo Achillis. 3, 3, Tendon of the Plantari9. 4, Peroneus Brevis. 5, 5, Flexor Digitorum Longus. 6, 6, The Flexor Pollicis Longus. 7, Tendon of Tibialis Posticus. 8, Tendon of Tibialis Anticus. 9, Extensor Digitorum Brevis. 10, 10, Tendon of Extensor Pollicis Proprius. 11, 11, 11, Common Extensor Tendons of Toes. 12, Short Flexor of the Toes. 13, Abductor Pollicis. 14, A branch from the Posterior Tibial. 15, Internal Malleolar Artery. 16, 16, Tarsal Artery. 17, Posterior Tibial Artery. 18, Internal Plantar Artery. 19, A superficial branch of same. 20, 20, Anastomosis between the preceding artery and Tarsal Artery. 21, 21, Twigs to Calcis. 22, The External Plantar Artery. 23, Internal Artery of Great Toe, or Sixth Digital Artery.

* Med. Chir. Trans., vol. vii. p. 234.

The Internal Plantar Artery

The Internal Plantar Artery is a branch of inconsiderable size: it advances above the abductor pollicis pedis; and after supplying this muscle, and the flexor pollicis brevis, terminates in branches which are distributed to the integuments of the great toe, and in anastomosis with the branches of the anterior tibial artery.