94 PROFESSOR OWEN ON THE OSTEOLOGY OF 
series, which series is straight when extended. It differs also in the more uniform 
transverse diameter of the bodies of the dorsal and lumbar vertebra, the latter not 
expanding in the same degree, as they approach the sacrum, as they do in the Human 
subject. These general differences in the relative position and proportions of the ‘ true’ 
vertebre are repeated, and are rather more strongly marked in the Chimpanzee and Orang. 
The comparison is instituted, throughout, with the Australian variety of the Human 
species—a variety, of which the entire skeleton, and the separate bones, have not 
hitherto been described and figured. 
The cervical vertebre of the Gorilla are the same in number as in the class Mam- 
malia generally, viz. 7. The number of dorsal vertebre, or those bearing moveable 
ribs, is 13; that of the lumbar vertebre 4; that of the sacral vertebre 5: the total 
number of true or moveable trunk-vertebree being the same as in Man, only the ribs 
which answerto the transverse processes of the first lumbar in Man retain their distinct- 
ness with a greater length, whilst those which form the transverse processes of the last 
lumbar vertebra become modified, by age, like the same elements of the sacral vertebre. 
Cervical Vertebre (Pl. XXXIII.).—Of the true vertebrz the cervical series departs most 
from the Human type in the extraordinary length of the spines of the last five vertebre 
(Pl. XX XIII. fig. 1, 3,4,5,6,7) ; that of the fourth cervical (4 ) being not less than 3} inches ; 
those of the third and fifth are nearly of the same length, but are thicker, and havea slight 
curvature in opposite directions, diverging in a slight degree away from the fourth; 
the spines of the sixth and seventh cervicals gradually decrease in length and increase 
in thickness: the spine of the dentata (2) is trihedral, the surfaces being divided by 
produced sharp ridges. The canal for the vertebral artery decreases in diameter from 
the sixth (7. fig. 6, v) forward to the atlas. 
The atlas (Pl. XXXII]. fig. 2) has a Jess transverse and a greater fore-and-aft diameter 
than that of Man (ib. fig. 8), with a wider neural canal (n), especially between the 
condyles (z), which are smaller than in Man. An obtuse process is developed back- 
wards from the part (hy) representing the body, which is broader than in Man; the 
perforation of the transverse process (v, fig. 3) is smaller, and that process is narrower, 
especially vertically, and is slightly recurved: the groove behind the upper articular 
processes is deeper and narrower. The neural spine is represented by a tubercle, which 
is more developed in the older male skeleton of the Gorilla in the Paris Museum. 
The axis or dentata (fig. 4 & fig. 1, 2) differs chiefly in the greater size of the neural 
canal, and in the greater length and less breadth of the neural spine. This, however, 
dilates at its extremity into a three-sided cone, with the broadest side downwards. 
The zygapophyses are smaller, the transverse processes’ are more directly perforated by 
the arterial foramina, and the diapophyses are more produced, and more remote from 
the posterior zygapophyses. The body is more quadrate behind. 
' This term is applied to the whole of the compound part marked d, p, and pi, in fig. 1,3; d being the 
diapophysis, p the parapophysis, and p/ the pleurapophysis. 
