162 THE ANATOMY OF THE HORSE. 



inner edge to the corresponding structure of the opposite side. Poster- 

 iorly, behind the summit of the 3rd dorsal spine, this cord is continuous 

 with the supraspinous ligament of the back. Anteriorly the cord is 

 inserted into a special tubercle on the occipital bone. Between these 

 points of attachment the cord extends with a slight upward concavity 

 when the ligament is relaxed, and above it there is developed, in vary- 

 ing amount, a quantity of fatty-elastic tissue supporting the integument 

 from which the mane grows. 



The lamellar portion is triangular in form, occupying the interval 

 between the funicular portion and the vertebral column. Its fibres 

 have a downward and forward direction, being fixed above to the funi- 

 cular portion or to the spines of the 2nd and 3rd dorsal vertebrae, and 

 below to the spines of the last six cervical vertebrae. The fibres are 

 stronger and more closely aggregated in proportion as they are anterior, 

 the lamella forming a complete septum in its anterior two-thirds, but 

 having the form of a network in its posterior third. The right and left 

 lamellae are applied together on the mesial plane, their inner faces being 

 united by areolar connective-tissue. 



The ligamentum nuchae assists in suspending the head ; and when 

 the head has been depressed it aids the muscles in elevating it again. 

 But for its presence, a large additional amount of muscular tissue 

 would have been necessary in the neck. In man, in whom the head is 

 supported by the spinal column, the ligament is very rudimentary, and 

 has lost its elastic texture. 



Directions. — The spinal column should now be disarticulated between 

 the 3rd and 4th cervical vertebrae ; and the head should be laid aside, 

 while the student proceeds to the dissection of the remaining liga- 

 ments of the neck. It will suffice to dissect carefully the ligaments 

 of one intervertebral articulation, — say that between the 4th and 5th 

 bones. 



The intervertebral joints of the neck posterior to the vertebra dentata 

 are constructed after a common plan, which is also that of the dorsal 

 and lumbar regions. Each vertebra is articulated to the preceding and 

 the succeeding bone (1) by an amphiarthrodial union of the bodies, and 

 (2) by diarthrodial joints between the articular processes. 



The atlanto-axial and occipito - atlantal joints, which are purely 

 diarthrodial articulations, will be dissected at a later stage. 



LIGAMENTS AND ARTICULATIONS OF THE NECK POSTERIOR TO 

 THE DENTATA. 



The ligaments may be classified into (1) those connecting the pro- 

 cesses and neural arches, and (2) those connecting the adjacent vertebral 

 bodies. 



