THE CHIMPANZEES AND ORANGS. 95 



The bodies of the succeeding cervical vertebrae are longer in proportion to their 

 breadth ; the basis of the neurapophysis ascends to embrace the hinder half of the 

 antecedent vertebra, as in Man. The difference observable in the dentata in regard 

 to the length of the spinous process is manifested in excess in the third cervical 

 vertebra ; the neural canal also exceeds that of Man in diameter ; the zygapophyses are 

 smaller than in Man ; the arterial canal (v) is transversely elliptic, not circular ; the 

 transverse process is longer, more slender and more simple, the pleurapophysial (p) 

 not projecting distinctly from the diapophysial (d) part ; the diapophysis is more 

 remote from the zygapophysis ; the neurapophyses are much thicker and stronger ; 

 the long neural spine ( 3 ) becomes subcompressed and slightly dilated at its extremity, 

 which is not bifurcate. 



The same general differences, and especially the very striking one in the length of the 

 neural spine, are manifested in the fourth cervical vertebra (PI. XXXIII. fig. 5), but the 

 pleurapophysial part (pi) of the transverse process is now distinctly developed as a trian- 

 gular depressed plate produced forwards and a little downwards ; the lower part of the 

 centrum is proportionally less than in Man, and the smaller size of the zygapophysis is 

 the more remarkable in contrast with the larger proportions of almost all the rest of the 

 vertebrae. In the fifth cervical vertebra the centrum (c) is smaller, but the zygapophyses 

 equal in size thoseof the corresponding vertebra in Man (fig. 12) ; the pleurapophysial 

 part of the transverse process (pi) is less developed than it is in the fourth, but is more 

 prominent than in Man : the arterial canal {v) is wider, the anterior and posterior zygapo- 

 physes are more nearly upon the same plane, and the neural arch (n) has a greater ante- 

 roposterior extent ; the superior thickness of the neurapophysis above these processes 

 is very striking. In the sixth cervical (fig. 1, 6, & fig. 6) the arterial canal of the 

 transverse process (v) increases in a greater degree than in Man (fig. 11); the pleurapo- 

 physial part (pi) of that process is more suddenly increased in length and breadth, and it 

 diverges more from the diapophysis (d) than in Man ; the zygapophyses (z', fig. 1) are 

 larger ; the neural spine (n s) is still very long and very strong, but is shorter than in the 

 antecedent vertebra (fig. s). The elongated spines of the last five cervical vertebrae are 

 a little expanded at their end [and this character is more marked in the skeleton of the 

 old male in the Paris Museum]. 



The atlas of the great Orang (Pithecus Wurmbii, PI. XXXIII. figs. 13, 14) departs in the 

 same way from the Human type, but in a greater degree than that of the Gorilla ; the 

 transverse diameter being still less in proportion to the fore-and-aft diameter, and the 

 transverse processes (d) being less developed : the neural arch (n) is more bowed and 

 slender. The vertebral artery, after perforating the transverse process, slightly grooves 

 the neural arch. The transverse extent of the bony bar (hypapophysis, hy) which holds 

 the place of the centrum, in proportion to the antero-posterior extent of the whole ver- 

 tebra, is greater than in Man : the flattened posterior articular processes (fig. 14, z') 

 are subelliptic or reniform, not subcircular as in Man, and the vertebral foramina (u) 



