MAMMALIA. 223 



spiral, and then proceed to the outer side of the last finger ; it passes deeply, 

 confined by a ligament at its entrance into the palm, and sends a branch for 

 the inner side of the last finger and the outer side of the third : the rest of 

 the nerve forming the deep palmar, divides into branches, which terminate on 

 the interosseous and other small muscles situated in the palm, and give 

 branches to join those of the median, sent to the outer side of the first and 

 the inner side of the second finger, and the outer side of the second and the 

 inner side of the third. 



11. Spiral nerve ; it has a slight communication with the fifth cervical, but is prin- 



cipally formed from the sixth and seventh, and first dorsal ; it gives branches 

 to the different heads of the triceps muscle, and winds round between the 

 inner and large heads of the triceps to the outside of the arm, and divides 

 into two large branches ; one gives off a large cutaneous branch to the outer 

 side of the fore-arm, and then descends in the place of the radial, giving 

 branches to the skin, and dividing to terminate on the skin at the back of the 

 hand and the side of each finger, except the outer side of the last, and 

 communicate with the dorsal branch of the ulnar ; the other, in passing to 

 the back of the fore-arm, gives a branch to the long and the short supinator ; 

 it is conducted between some fibres of the short supinator, and then divides 

 to terminate in the radial extensor of the wrist and the extensor of the 

 fingers, whilst a long branch passes on and gives filaments to the muscles 

 analogous to the extensors of the thumb, and to the wrist-joint, but does not 

 terminate on this part in a ganglion as in man and the baboon. 



12. Last dorsal nerve ; there are thirteen dorsal nerves, and their principal 



deviation from those in man consists in a smaller size, a more direct course, 

 and a less distribution on the abdominal muscles, and by those at the lower 

 part of the chest being covered by an extension of the origin of the psoas 

 muscle ; and in the anterior cutaneous branches supplying the different 

 portions of the mamma in the female dog as well as the skin : the posterior 

 trunks, after supplying the muscles connected with the spine, and the sacro- 

 lumbar and longest muscles of the back, send a branch between fibres of 

 these and the broadest muscle of the back to the skin. 



