THE BRACHIAL PLEXUS. 



869 



differences in the branch of the anguhn-i^ and rhomhovleus, in the branches of the pectoral 

 muscles, the subcutaneouii thoracic branch, or the anterior brachial or musculo-cutaneouB nerve. 



Tlie nerve of the serratus magnus does not sliow the bniuch which, iu the Horse, arises from 

 the sixth nerve and passes through tlie scalenus; but on the surCace of the serratus magnus it 

 jeceives a filament from the brancli of the angularis. The latter is detached from tlie sixth. 



The branch of the l(iti>"'irnus dorgi muscle and the axillary nerve are confounded at their 

 origin, and also adluiv (o one of the two 



Fig. 4-68. 



branches of the gnbfcapularis nerve. The 

 second branch of the latter is tree through- 

 out it.s extent, and distiibiited m the mus- 

 cle of the same name, along with some fila- 

 ments furnished by the supra-scapnlari'S. 



The radial nerve, when it reaches the 

 teres major, divides into three branches: 

 one is buried in the long extensor of the 

 forearm ; the other traverses the middle 

 extensor; and the third is inflected on the 

 tendon of tlie latissimus dorsi,and passes 

 between the middle and large extensor 

 of the forearm. When the radial nerve 

 turns outwards around the arm, and is 

 placed between the anterior brachial and 

 the mass of the olecranian muscles, it 

 furnishes ; 1. Muscular branches that pass 

 immediately beneath the extensors of the 

 metncarpus and phalanges. 2. A sensitive 

 branch thatleavestliis muscular interstice 

 to become subcut. menus. This cutaneous 

 branch of the radial nerve gains the inner 

 face of the forearm, and divides in two 

 branches that descend parallel to the 

 median subcutaneous vein. One of these 

 is distributed around the carpus; the 

 other is placed a little in front of the meta- 

 carpus, and reaches thenn tacarpo-pl alan- 

 geal articulation, where it terminates by 

 two principal filaments that constitute the 

 dorsal collaterals of the digits ; there is 

 a third which crosses the interdijiital to 

 anastomose with the palmar collateral."}. 



The ulnar and median nerve of Rumi- 

 nants lie besi<le each other, as far as the 

 middle of the arm. This double cord la 

 situated at the surface of the humeral 

 artery ; at the carpus tlie two nerves offer 

 the same distribution as in the Horse, but 

 beyond this there are some differences. 



The ulnar does not receive a branch 

 from the median at the carpus, and it 

 forms the external plantar nerve or inter- 

 osseous palmar of the second space, placed 

 at the external border of the flexor tendons. 

 This nerve is reinforced by a filament de- 

 tached from the external plantar, that 

 joins it a little above the fetlock -joint ; it 

 gives ramuscules to the ergot, and is then 

 continued by the external collateral nerve 

 of the onter digit, into the toe. 



The median is continued by tlie internal plantar, or interosseous palmar of the third space. 

 Towards the inferior third of the metacarpus, it divides into three branches: tJie third passes 

 to the external plantar ; the second proceeds to the interdigital space, where it bifurcates to 

 form the internal collater(d palmar nerves of the external digit, and external collateral of the 



NERVES OF THE DIOITAI; REGION OF RUMINANTS 

 fPOSTKRIOR face). 



M, Internal plantar nerve, a continuation of the 

 median : c, internal plantar nerve, a continuation 

 of the ulnar. 1, Branch of the plantar, furnishing, 

 2, the internal collateral nerve of the internal 

 digit; .3, branch giving otf the internal collaterals 

 of the digits ; 1', branch of the internal plantar 

 that joins the external plantar ; 4, external col- 

 lateral of the external digit. 



