THE VERTEBRAL COLUMN. 7 
facets. Thus from the tenth to the thirteenth thoracic vertebra 
rotary motion is very limited, owing to the interlocking of the 
articular processes. 
The Lumbar Vertebre. Vertebre lumbales (Fig. 5).— 
The last thoracic vertebre form the transition to the typical 
lumbar vertebra. These are larger than the thoracic vertebra. 
cA 
Fic. 5.—LuMBAR VERTEBRA. 
a, cranial articular processes; 4, mammillary processes; ¢, caudal articular processes; @, accessory 
processes; ¢, transverse processes; /, spinous processes. 
4“ 
The centra are of the form of the centra of the thoracic vertebrz, 
and increase in length to the sixth, but the seventh is about. 
the length of the first. They increase in breadth to the last.. 
