THE SPINAL COLUMN OF QUADRUPEDS. 139 



that, at the jjoint of junction between the dorsal 

 and kimbar portions of the vertebral column, 

 the spinous processes of each part must meet in 

 abrupt opposition. This, however, is not pre- 

 cisely the case; for if it were, the centre of 

 motion in the spinal column would necessarily 

 lie between two vertebrce, and the flexiu-e 

 would be acute. There is a transition from 

 the posterior-oblique bearing of the spinous 

 processes of the dorsal, to the anteriorly- 

 oblique bearing of those of the lumbar vertebrse; 

 the processes of the lower dorsal and upper or 

 anterior lumbar vertebra gradually assuming 

 a horizontal direction in man, or a vertical 

 direction (according to their attitude) in quad- 

 rupedal mammalia. So that, instead of being 

 confined to one point, the centre of motion is 

 diffused over the space of the three or four last 

 dorsal, and two or three first lumbar vertebra, 

 an abruptly acute curve being thus avoided. 



"Professor Owen observes, that 'the relation 

 which the structure of the vertebral column 

 bears to the mode of a quadruped's loco- 

 motion is extremely interesting, and enables 

 us to judge, in some degree, from the spine 

 alone, of the locomotive faculties of a fossil 

 species.' If we attend to the progressive 



