THE EXTERNAL ILIAC ARTERIES. 551 



artery which is of considerable size in other animals. Placed within the 

 external metatarsal bone, it anastomoses, by its inferior extremity, with a 

 branch of the metatarsal pedal artery. The internal interosseous plantar artery 

 may be considered, if we would neglect the study of analogies, as the continua- 

 tion of the perforating pedal artery, which it rivals in volume. It descends 

 to the external side of the internal metatarsal bone, beneath the margin of the 

 suspensory ligament of the fetlock, and terminates a little above the tubercle 

 of the external metatarsal bone, in uniting at a very acute angle with the 

 metatarso-pedal artery. It gives off on its tract : the medullary branch of 

 the principal metatarsal bone ; a small branch to the external interosseous 

 artery ; several ramuscules which transversely cross the posterior border 

 of the internal metatarsal bone to supply the cellular tissue, the skin, and 

 the tendons applied to the median metatarsal bone. 



2. Anterior Tibial Artery. (Fig. 278, 1.) 

 Preparation. Expose the artery by removing the anterior muscles of the leg. 



The anterior tibial artery is the largest of the two branches terminating 

 the popliteal trunk. It traverses the tibia 1 , or tibio-peroneal arch, and, with 

 its satellite veins, places itself on the anterior aspect of the tibia, down 

 which it passes by following the deep face of the flexor muscle of the 

 metatarsus. On reaching the front of the tibio-tarsal articulation, it loses 

 its name and takes that of the pedal artery. 



The anterior tibial artery gives off a great number of collateral branches, 

 which are principally distributed among the tibial muscles. One of them, 

 descending along the fibula, beneath the lateral extensor muscle of the 

 phalanges, clearly represents a trace of the peroneal artery of Man. 



3. Pedal Artery. (Fig. 278, 1 .) 



A continuation of the anterior tibial artery, whose name changes on its 

 arrival in the region of the foot, the pedal artery courses downward over the 

 anterior face of the tibio-tarsal articulation, by bending slightly outwards, 

 and passing beneath the cuboid branch of the flexor muscle of the metatarsus. 

 At the second row of tarsal bones it divides into two branches, which we 

 will designate the perforating pedal, and the metatarso-pedal arteries, 1 the 

 latter continued interiorly by the digital arteries, or collaterals of the digit. 



The collateral branches emanating from this vessel are all articular 

 cutaneous, and of no importance. 2 



PERFORATING PEDAL ARTERY. It crosses the tarsus from before to 

 behind, by passing, with a venous branch, into the canal between the 

 cuboid, scaphoid, and great cuneiform bones ; it then joins the arch formed 

 by the anastomoses of the two plantar arteries terminal divisions of the 

 posterior tibial (Fig. 278, 2). 



METATARSO-PEDAL OR COLLATERAL ARTERY OF THE CANNON. S Much 



1 The vessel \ve have here named the perforating pedal artery is only the like 

 termination of the same artery in Man. The metatar so-pedal artery ought to be regarded 

 as the representative of one of the dorsal interossei arteries, because of its position in the 

 interstice of the middle and external lateral metatarsal bones. The dorsal interstice of 

 the inner side also lodges an interosseous branch, usually supplied by the external 

 plantar artery ; but its diameter is so diminished that, in order to avoid complexity by 

 introducing an almost useless element into the didactic description of the posterior 

 tibial artery, we have thought it our duty to neglect its indication. 



2 One of these may be regarded as the analogue of the dorsalis pedis of Man. 



3 Rigot has designated this artery we do not know why the superficial plantar artery. 



