846 THE NERVOUS SYSTEM OF THE PIG 
The brachial plexus is derived from the same nerves as in the ox, but the root 
furnished by the sixth cervical is relatively smaller. The plexus consists of two 
parts, the upper of which emerges above the scalenus, the lower between the two 
parts of that muscle. The more important differences in the nerves emanating 
from the plexus from the arrangement in the ox occur in the distal part of the limb. 
The cutaneous branch of the radial nerve divides at the carpus into branches which 
concur with the dorsal branch of the ulnar nerve in supplying the dorsal digital 
nerves, two for each digit. The volar digital nerves, also two for each digit, are 
formed by the terminal branches of the median nerve and the volar or deep branch 
of the ulnar nerve. The formation and arrangement of the digital nerves are 
indicated in the annexed schematic figures. 
The lumbo-sacral plexus is derived from the ventral branches of the last three 
Deep peroneal 
nerve ' ES i 
__- Saphenous Tibial nerve ~— 
nerve 
Superficial 
peroneal nerve 
_- 
Medial plantar ~~ Teatera? 
Mee |. __ plantar 
NET VE 
_- Dorsal 
branch 
Anasto- 
és 5 
motic 
branch 
Fic. 675.—Nerves or DistaLt Part oF Ricat Hinp Fic. 676.—Nerves or Distat Part or Ricut Hind 
Lima oF Pic; DorsaLt View (SCHEMATIC). Lims or Pic; PLANTAR ViEW (SCHEMATIC). 
p, Dorsal proper digital nerves. p, Plantar proper digital nerves. 
lumbar and first sacral nerves. The distribution of the branches of the plexus 
differs chiefly in the distal part of the limb. The superficial peroneal nerve is 
large and terminates by forming the greater part of the dorsal digital nerves. 
The latter, two for each digit, are also in part formed by the terminal branches of 
the deep peroneal nerve. 
The tibial nerve divides at the tarsus into medial and lateral plantar nerves. 
The latter divide to form the plantar digital nerves, two for each digit. In addi- 
tion, the lateral plantar nerve supplies a branch to the dorsal aspect of the lateral 
(fifth) digit. The arrangement of the digital nerves is indicated by the annexed 
schematic figures. 
The sympathetic system of the pig has received very little attention from 
anatomists. The anterior cervical ganglion is long and fusiform. It gives off 
