636 TEE ARTERIES. 



3. Pedal (or Great Metatarsal) Artery (Fig. 371, 2). 



A continuation of the anterior tibial artery, the name of which changes on 

 reaching the region of the foot, the pedal artery courses downward over the 

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

 passing beneath the cuboid branch of the flexor metatarsi. At the second row 

 of tarsal bones it divides into two branches, which we will designate the im-foraU 

 ing pedal (or perforating metatarsal), and the metatar so-pedal arteries,^ the latter 

 continued inf eriorly by the digital arteries, or collaterals of the digit. 



The collateral branches emanating from this vessel are all articular or 

 cutaneous, and of no importance.^ 



Perforating Pedal (Arteria Pedis Perforans, Perforating Meta- 

 tarsal) Artery. — It crosses the tarsus from before to behind, by passing — with 

 a venous branch — into the canal between the cuboid, scaphoid, and great cunei- 

 form bones ; it then joins the arch formed by the anastomoses of the two plantar 

 arteries — terminal divisions of the posterior tibial (Fig. 371, 14). 



Metatarso-pedal or Collateral Artery of the Cannon.^ — i\Iuch larger 

 than the preceding, this vessel (Fig. 371, 3) may be considered as a continuation 

 of the pedal (or great metatarsal) artery. It is lodged at first in the fissure 

 situated outside the large metatarsal bone, in front of the external metatarsal 

 bone, and afterwards passes between these two bones, above the tubercle termi- 

 nating the latter, reaching the posterior face of the first, between the two inferior 

 branches of the suspensory ligament, above the sesamoid groove, where the 

 vessel bifurcates to form the collateral arteries of the digit. 



The collateral artery of the cannon receives, a short distance above this 

 terminal bifurcation, the internal plantar interosseous artery. 



On its course it gives off : 1. Numerous anterior ramuscules for the connec- 

 tive tissue, tendons, Ugaments, and the skin on the anterior face of the meta- 

 tarsus and fetlock. 2. Some slender posterior divisions, one of which ascends 

 within the external plantar interosseous artery, after furnishing several liga- 

 mentous, tendinous, and cutaneous ramuscules in the posterior metatarsal region. 



Digital Arteries, or Collateral Arteries of the Digit (Figs. 370, 25 ; 

 371, 5, 5 ; 377, 11). — Remarkable for their volume, these arteries carry blood 

 to the keratogenous apparatus enveloping the ungual phalanx, and from this 

 distribution derive such importance that they deserve a detailed study. 



' The vessel we have here named the perforating pedal artery, is only the like termination 

 of tlie same artery in Man. The metatarso-pedal artery ought to be regarded as the represen- 

 tative of one of the dorsal iuterossei 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 tliat, 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. 



* One of these may be regarded as the analogue of the dormlis pedis of Man. 



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

 It would have been better to have allowed it to retain the name given to it by Girard— the 

 lateral artery of the cannon. This is not the only instance in which the attempts of Rigot to 

 conform the nomenclature of the arteries to that of anthropotoraists has proved unfortunate, as 

 he has not always succeeded in finding in the Horse the real representatives of the arteries in 

 Man. The aim of this work does not allow us to discuss the vicious determinations and 

 denominations of Rigot every time we meet them. We are content to change them, purely 

 and simply, leaving to the judgment of the reader, should this matter interest him, the task 

 of deciding if we are right. 



