THE DISTBIBUTION OF THE SPINAL NEKVES. 



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2. Ventral Surface. 



(Medial side and lack of thigh, lack of leg, and sole of foot.) 



A Innervation of the Muscles of the Limbs. The following laws appear to be applicable 

 to the upper and lower limbs alike : 



No limb-muscle receives its nerve-supply from posterior rami. 



2. The dorsal and ventral strata of muscles are always supplied by the corresponding dorsal and 

 ventral branches of the nerves concerned. The ventral muscular stratum is more extensive than the 

 dorsal ; the ventral nerves are the more numerous, and the additional nerves are postaxially placed. 

 The spinal nerves supplying muscles of the upper limb are C. 5, 6, 7, 8 (dorsal), and C. 5, 6, 7, 8, 



1 (ventral) ; the nerves for the muscles of the lower limb are L. 2, 3, 4, 5, S. 1, 2 (dorsal), and 

 L 2, 3, 4, 5, S. 1, 2, 3 (ventral). 



. The dorsal and ventral trunks of the nerves are distributed in the limb in a continuous, 

 segmental manner ; so that, " of two muscles, that nearer the head end of the body tends to be 

 supplied by the higher nerve, and that nearer the tail end by the lower nerve " (Herringham). 



4. ^ The nerves placed most centrally in the plexus extend furthest into the limb, and the more 

 oreaxial nerves terminate sooner in the limb than the more postaxial nerves. 



