48 PHYSIOLOGICAL SERIES. 



B. 9. Back of the skull, with cervical and four dorsal vertebrae, 

 of a Sheep (Om (tries), showing the (ligamentum nuchae) 

 snpraspinous elastic ligament. It consists of two rounded 

 bundles of yellow elastic tissue fused in the mid line, attached 

 in front to the occipital tubercle, and strengthened by a 

 broad bundle springing from the spines of the 2nd, rrd, 

 4th, and 5th vertebrae. The two bundles becoming flattened 

 extend backwards as far .as the sacrum, greatly diminishing 

 in size. They are attached to the neural spines, especially 

 those of the anterior dorsal vertebrae. This ligament serves 

 as an elastic support to the head and neck. 



B. 10. A similar preparation from a Uog (Catris familians). 

 The ligament springs as a round cord from the posterior 

 angle of the spinous process of the second vertebra. It 

 passes backwards without further attachment in the neck, 

 and is fixed to the tips of the spines of the dorsal and 

 lumbar vertebrae. This arrangement appears to give to the 

 head greater freedom for movement. 



INTERSPINOUS. 



B. 11. Five dorsal vertebrae of a Crocodile (Crocodihis acutns), 

 with portions of ribs attached. The spinous processes are 

 united by yellow elastic tissue, forming an interspinous 

 elastic ligament. 



B. 12. Three inferior cervical vertebrae of an Ostrich (Struthio 

 camelus) showing the deep interspinous elastic ligament. 



B. 13. Cervical vertebra of an Ostrich (StrutMo camelus). The 

 spinous process has been removed to show the attachments 

 of the elastic ligaments. 



B. 14. Three dorsal vertebrae of an Ostrich, longitudinally bi- 

 sected, to show a similar disposition of elastic ligament 

 between the spinous processes of this part of the vertebral 

 column. 0, C. 72, ffunterian. 



