552 



THE ABTEBIES. 



larger than the preceding, ttis vessel (Fig. 278 3) may be -n^dered as a 

 continuation of the primitive pedal artery. It is lodged at first in the 

 fis"ituated outside the middle metatarsal bone m front of the external 

 metatarsal bone, and afterwards passes between these, two bones above he 

 tubercle terminating 'the latter, reaching _ the posterior face of the fiist, 

 between the two inferior branches of the suspensory 

 Kg 278 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 cellular tissue, tendons, ligaments, 

 and the skin on the anterior face of the metatarsus and 

 fetlock ; 2, Some thin posterior divisions, one of vrhich 

 ascends within the external metatarsal bone to anastomose 

 with the external plantar interosseous artery, after fur- 

 nishing several ligamentous, tendinous, and cutaneous 

 ramuscules in the posterior metatarsal region. 



Digital Abtebies, oe Collateral Abteries op the 

 Digit (Figs. 277, 25; 278, 4; 283, 11).— Eemarkable 

 for their volume, these arteries carry blood to the 

 keratogenous apparatus enveloping the ungual phalanx, 

 and from this destination derive such importance that 

 they deserve a detailed study. 



Origin. — The digital arteries succeed the terminal 

 extremity of the collateral of the cannon, and separate 

 from one another in forming an acute angle below the 

 sesamoid venous arch, above the fetlock joint, between 

 the two branches of the suspensory ligament, behind the 

 inferior extremity of the principal metatarsal bone, and 

 in front of the flexor tendons of the phalanges. 



Course and Belations. — These vessels descend, one to 



the right, the other to the left, from the lateral parts of 



the metacarpo-phalangeal (and metatarso-phalangeal) 



articulation to the internal face of the basilar process, 



principal arteries -(viiere they bifurcate to form the plantar and preplantar 



T MOR °oo™'' ™3"«"^ ^'■'*"«^- 



1, Interior tibial ^r- , "'^'^ the whole of this course it (the digital artery) 



tery • 1', Pedal ar- follows the track 01 the flexor tendons, on whose margin 



tery ; 2, Perfora- it rests, and where it is maintained by loose connective 



ting pedal artery ; tissue. Behind, it is flanked by the plantar nerve, which 



3, Metatarso-pedal, 

 or collateral artery 

 of tlie cannon; 4, 

 Digital artery ; 5, 

 Anterior tibial ar- 

 tery ; 6, Posterior 

 root of the internal 

 saphena vein ; 7, 

 Origin of the ex- 

 ternal saphena vein ; 

 8, 9, 10, Metatarsal 

 veins; 11, Digital 

 vein ; 12, Venous 

 plexus of the foot. 



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 Kigot to coaform the 

 nomenclature of the arteries to that of anthropotomists has proved 

 unfortunate, as he has not always succeeded in finding in the 

 Horse the real representatives of arteries in Man. The aim of 

 this work does not allow ua 1o 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 reailer, should this matter interest him, the task 

 of deciding if we are right. 



