264 ZOOTOMY. 



above to form the neural arch, through which the spinal 

 cord passes : each neurapophysis consists of a ventral, 

 somewhat cylindrical portion, the peduncle, and of a 

 dorsal flattened portion, the lamina. 



11. The neural spine, an elongated, backwardly 

 directed process proceeding from the apex of the neural 

 arch at the junction of its two laminae. 



12. The transverse processes, short stout rods pro- 

 ceeding directly outwards one from each side of the neural 

 arch at the junction of the peduncle and lamina. 



13. The anterior zygapophysis, a small horizontal 

 process projecting forwards from the anterior face of each 

 neurapophysis at the junction of the peduncle and lamina : 

 its dorsal surface is flat and smooth, forming an articular 

 facet. 



14. The posterior zygapophysis, a slight projection 

 of the postero-ventral region of each lamina, bearing an 

 articular facet on its under side.' 



15. In the young skeleton, the epiphyses, two thin 

 bony disks, closely applied one to the anterior the other to 

 the posterior face of the centrum to which they are ankylosed 

 in the adult. 



In the young subject the epiphyses easily separate from the vertebra 

 proper, to which, indeed, they are less firmly attached than to the inter- 

 vertebral ligaments (§ 27) ; it therefore often happens, in maceration, 

 that an epiphysis becomes detached from its own vertebra, but remains 

 united to the next by the intervertebral ligament. 



The free surfaces of the epiphyses are smooth ; their inner surfaces, in 

 contact with the centrum, are rough, as also are the faces of the centrum 

 itself : the centrum presents two oblique grooves, corresponding to the 

 neuro-central sutures (§ 16), and equally well marked whether the latter 



^ It is useful to remember that the anterior face of a vertebra can 

 always be told by observing the zygapophyses : the facets of the anterior 

 zygapophyses look upwards, inwards, or forwards, those of the posterior 

 zygapophyses downwards, outwards, or backwards. 



