POSTERIOR PRIMARY DIVISIONS. 



279 



Pig. 188. SUPERFICIAL AND DEEP DISTRIBUTION OP THE POSTERIOR PRIMARY DIVISIONS OP THE SPINAL 

 NERVES. (After Hirschfeld and Leveille. ) i 



On the left side the cutaneous branches are shown lying upon the superficial muscles; on the 

 right side, these muscles having been removed, the splenius and complexus have been divided in the 

 neck, and the erector spinse separated and partially removed in the back, so as to expose the deep 

 portions of the nerves. 



a, a, small occipital nerve from the cervical plexus ; 1, muscular branches of the first cervical nerve 

 and union by a loop with the second ; 2, placed on the rectus capitis posticus major, marks the great 

 occipital nerve passing round the inferior oblique muscle and piercing the complexus ; the external 

 branch is seen to the outside ; 2', cranial distribution of the great occipital ; 3, external branch of the 

 posterior primary division of the third nerve ; 3', its internal branch, or third occipital nerve ; 4', 5', 

 6', 7', 8', cutaneous offsets from the internal branches of the cervical nerves on the left side ; the external 

 branches of these nerves proceeding to muscles are displayed on the right side ; d 1 to d 6, and thence 



