THE PERIPHERAL NERVOUS SYSTEM. 385 



the two divisions of this muscle, and supplies the skin and 

 cutaneous muscles between the two external ears. The dorsal 

 rami of the other cervical nerves supply muscles and integu- 

 ment on the back of the neck. 



Ventral Rami (rami anteriores). These pass ventrad 

 between the transverse processes of the vertebrae, except in the 

 case of the first nerve (Fig. 156,^'). This passes ventrad from 

 the atlantal foramen along the groove for the vertebral artery, 

 through the notch in the wing of the atlas, and across the lateral 

 surface of the longus capitis muscle (5). Here it sends a 

 branch caudad to join the second cervical (), then crosses the 

 vagus (d'} and sympathetic and the carotid artery, giving off 

 communicating branches to the vagus and sympathetic, and 

 uniting with a branch of the descending ramus of the hypo- 

 glossal (/). At the lateral surface of the larynx it turns 

 caudad, following the lateral border of the sternothyroid muscle 

 (7), and is distributed to the sternohyoid (s) and sterno- 

 thyroid (?). 



The ventral ramus of the second nerve (Fig. 158, 2) 

 receives a branch from that of the first nerve, passes laterad 

 between the levator scapulae ventralis (c] and the cleidomastoid 

 (*/), receives a communicating branch from the third cervical 

 (3), sends a branch to N. accessorius (i) and numerous small 

 nerves into the sternomastoid (e~] and cleidomastoid (d], then 

 turns craniad and divides into N. auricularis magnus (5} and 

 N. cutaneus colli (6). 



N. auricularis magnus (5), the great auricular nerve, 

 passes dorsocraniad across the lateral surface of the sternomas- 

 toid (e) to the lateral and caudal surface of the external ear and 

 parotid gland (/), where it ramifies. The cutaneus colli (6) 

 is the smaller, ventral, division of the second nerve; it may 

 receive also an accession from the third. It passes to the 

 integument over the ventral part of M. masseter and ventrad 

 of that muscle. 



The third nerve (Fig. 1 58, 3) communicates with the second 

 and supplies the levator scapulae ventralis (^), cleidomastoid 

 (d], sternomastoid (r), longus capitis, and other muscles of this 

 region and aids in forming the cutanews colli (e). The fourth 



