////: nii.iriiiM. nit .I\II.I.M;Y M;TI:I;IES. 571 



r m.lial artery ; the posterior trovorec-i the inferior radio-nlnar ;:r -li. to distribute 

 the innjority "' i'- s blanches behind tin- carpal articulations. 



Id. Radio-palmar itrt-nj. Ari-in;.', 03 w have already seen, from the posterior 



radial artery, towards tin- npp-r thinl of the fore-arm, this branch dcmvnds to the 



SIIJH rior exticinity of tlie met icurpns in following, as in the Horse, a buperlii-i.il conr-e. 



and i nds in four ;/i<ric(i/'/i/ interosstou* <ir/>r/'x; three posterior nr jxilnmr, and one 



>r or dorsal. The porter/or tntaroMMMM artetiM are very irregular ami inconstant 



iu their di.-p >.-ition ; tliey communicato with each other by several hraveiu s. and 



. interiorly, either with the lateral digital arteries, the collateral of the cannon, 



ur. as is ino.-t i ini'>nly the case, with a branch of the latter vessel. These intcrosseous 



arteries are distinguished into external, middle, and internal ; tho first two are compri* d 

 ii the posterior face of the metacarpus and the suspensory ligament; the third, 

 placed at the inner border of that ligament, is more considerable than the others, and l>y 

 its volume and direction represents tho continuation of the radio-palmar artery. The 

 'or interosseous artery passes through tho foramen at the superior extremity of the 

 metacarpus, and arriving at the dorsal face of the bone, it bifurcates, its ascending 

 branch reach ing the capsular ligament of the carpal articulations, where it anastomoses 

 with the divisions of the anterior radial and interosseous nrteries of the fore-arm; tho 

 M'ling is lodged in the anterior groove of the metacarpal bone, and joins a perforating 

 branch of the collateral uitery of the cannon a branch which crosses the foramen 

 1 towards the inferior extremity of the bony diaphysis. If it is desired to ascertain 

 unification of these interosseous arteries in their relation to the elements composing 

 the 1'oot of Kumiijunts, we readily recognise: in the posterior median artery, the 

 intt rosseous palmar of the two great digits; in the posteiior lateral arteries, the 

 interosseous palmar, intermediates to these middle digits, and the rudimentary lateral 

 represented by the ergots or dew claws ; and in the single anterior artery, the dorsal 

 interosseous of the two great digits. We may even prove, by a more minute examination, 

 \istence of dorsal interosseous arteries corresponding to the lateial palmar inter- 

 osseous vessels. 



11. Collateral artery of the cannon. This artery follows the same track as in the 

 Horse, as far as the lower third or fourth of the metacarpus. Arrived at this point, it 

 abandons, as in the Horse, a branch whose divisions communicate with the interosseous 

 arteries, and are continued by the digital arteries, three in number: a middle and two 

 lateral (Fig. 349). 



d. The communicating branch icith the metacarpal interosseous arteries very often 



from the internal digital artery. 



It is insinuated between the divisions of the suspensory ligament, and ascends on the 

 posterior face of the metacarpus, breaking up into a number of branches which nearly 

 all join the precited arteries, or even the lateral digital, in affecting a variable and 

 complicated disjwsition which it is needless to notice here. One of these branches a 

 true jH-rj'iriiti'mj nft-nj, traverses the inferior extremity of the cannon bone, 

 in it- anterior u r rove to join the anterior interosseous artery, after detaching ramn 

 to the metaoarpo-phalangeal articulation. 



//. The niiil'II' iliijitul urti ry represents, by its dimensions, tho continuation of the 

 collateral artery of the cannon, and is a very voluminous vessel. It is at tirst in;' 



> ards arid outwards to lv placed on tho posterior face of the perforatns tendon ; th-n 

 it de.-e. : , :.- into the interdigital space by passing behind the great se*ainoid sheath, 

 I'nent uniting the two clav> ML; tin; inferior extremity of tho 



halanx, it divides into two Hiujurtil urlrriK, "if for e.ieh di-it, which are inflected 

 forwards, puss beneath the internal lig.nnent common to the two inti rphalaiii,'eal articu- 

 lations, and enter by the foramen pierced at tin- inner .-ide <>f the pyramidal em: 

 into the internal sinus of the third phalanx, where each ramifies in the saiui; manner 

 plantar ungiieal arteries of the li 



.'ral collateral liram-he-, r. markahle for the richness of their arlmrisations, e 

 from thH i <y of the digits and its terminal di\i.Moiis. The m< st im|M>rtant of 



are: 1. At the middle of the first phalanx, two short tr.msversc branches -a right 

 and left, passing beneath the flexor tendons and going from the median digital artery 

 to the !a. ral ai t. ii .- of the digits; 2, Nearly at the Mime point, a >ini_'li- artery which 

 ix.-s the interdigital sjce from IN hind t > l>efore, to pata between the two ten. Ions 

 of the common ,-\t. n-or of the' phalanges whence it ramifies on the anterior : 



ling along the anterior median vein, and im; with a 



descending branch nt -ing artery which crosses tho inferior extremity 



in. laearpus ; ;;. A doub.o branch analogous to the artery of the plant ir cn.-hioii of the 



. having its origin at the terminal extremity of the digital art. ry. i>ft. n arising fn.in 



the nii'.'in-al artery either on one side or Uth, and C"inn. in. Latin:-. !> a! ;unch, 



