OF THE MUSCLES. 



105 



and wing of the atlas ; as well as into the second, third, 

 fourth, and fifth cervical transverse processes. Action. One 

 muscle contracting would draw the head to that side ; both 

 would curve the neck, and operate in the rapid movements 

 to raise the head. 



FIG 4. 



THE NECK, WITH THE LEVA- 

 TOR HUMERI REMOVED, 



1, The splenius. 



Trachelo mastoideus (Plate III. 3). Origin. From the 

 transverse processes of the first two dorsal vertebrae ; and 

 the oblique process of the last cervical vertebrae. Insertion. 

 Into the temporal bone and wing of the atlas; by tendon, 

 which is common also to the splenius. Action. — Separate 

 action. To turn the head, or bring it to one side. Combined 

 action. These muscles might be regarded as continuations 

 of the longissimus dorsi. They will fix the neck in rearing 

 and leaping ; or assist in raising and keeping steady the 

 head. 



CoMPLEXUS MAJOR (Plate III. 2). Origin. By tendon, 

 common also to the splenius, from the anterior six dorsal 

 spines ; and by tendon, likewise shared by the longissimus 

 dorsi, into the transverse processes of the same dorsal ver- 

 tebrae. Insertion. Into the occiput ; and into the last six 

 cervical vertebrce. Action. To aid the ligamentum colh in 

 supporting the head. Its thick short, intersected, muscular 



