NERVES OF MAMMALIA. 171 



the great pectoral muscle ; a nerve proceeding principally from 

 the last cervical and first dorsal supplies the subscapularis. teres 

 major, and latissimus dorsi, then takes a circumflex course to the 

 deltoid, and external head of the triceps, and finally passes down 

 the limb to the skin. The external branches of the third and 

 fourth dorsal nerves, also, supply the skin ; the internal cutaneous 

 nerve is sent off from the ulnar. The musculo-cutaneous is 

 formed chiefly by the last cervical, and partly by the first 

 dorsal ; it contributes to the formation of the median nerve, 

 then pierces the coraco-brachialis to terminate on the biceps. 

 The median is mainly formed by the first two dorsal nerves ; it 

 sends a branch to the biceps, brachialis internus, and supplies the 

 skin on the posterior and inner part of the fore-leg. After 

 supplying the flexors on the fore-leg, it sends a nerve close to the 

 bone which gives filaments to the periosteum, and passes to a 

 muscle answering to the flexor longus pollicis : it then passes 

 underneath the annular ligament, and sends a large branch 

 obliquely over the flexor tendons to communicate with the ulnar 

 nerve, and descends, giving off branches to the skin at the inner 

 side of the foot, which communicate with the inner portion of the 

 deep palmar branch of the ulnar : it then passes to vascular 

 lamella? attached to the hoof, fig. 17, 17, to terminate on these, on 

 the villous part of the sole and the ligaments of the joints. The 

 ulnar nerve arises from the first and second dorsals ; at the middle 

 of the arm it sends off the internal cutaneous nerve, and at the 

 elbow gives some branches to the short extensor and the elbow 

 joint; it passes down, covered by some fibres of the flexor 

 muscles, and at the wrist sends off the dorsal branch to the skin 

 at the posterior and outer part of the fore-leg ; it passes under- 

 neath and to the inner side of the flexor carpi ulnaris, and then 

 underneath the annular ligament, and gives off the deep palmar 

 nerve : it receives the branch from the median, and descends, 

 o-ivino; branches to the skin and ligaments at the outer side of the 



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foot, after these have communicated with the outer branch of the 

 deep palmar ; it passes into the foot, covered by the vascular 

 lamellae connected with the hoof, and terminates on these, the 

 villous part of the sole and the ligaments of the joint. The deep 

 palmar gives some filaments to the ligaments, and divides into 

 two principal branches, one to pass on the inner side to give 

 filaments to the joints, the periosteum, and ligaments, and com- 

 municate with the branches of the median sent to the skin and 

 ligaments at the inner side of the foot, the other to s;ive filaments 



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to the periosteum and ligaments, and communicate with branches 



