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 vertebrze, except in the 
case of the first nerve (Fig. 156, 7). 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 (4), then crosses the 
vagus (@’) 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 (8) and sterno- 
thyroid (7). 
The ventral ramus of the second nerve (Fig. 158, 2) 
recéivés a branch from that of the first nerve, passes laterad 
between the levator scapule ventralis (c) and the cleidomastoid 
(2), receives a communicating branch from the third cervical 
(8), sends a branch to N. accessorius (1) 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 (¢) 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. 158, 3) communicates with the second 
and supplies the levator scapulz ventralis (¢), cleidomastoid 
(d@), sternomastoid (¢), longus capitis, and other muscles of this 
region and aids in forming the cutaneus colli (¢). The fourth 
