THE VERTEBRAL COLUMN. 11 
the fused transverse processes of the second and third sacral 
vertebre. 
Caudal Vertebre. Vertebre caudales (Fig. 1, y, and 
Figs. 8 and 9).—The caudal vertebre (21-23 in number) 
decrease gradually in size to the last one. Caudad they 
become longer and more slender 
and lose the character of verte- 
bre. They become finally re- 
duced to mere centra,—-slender 
rods of bone knobbed or enlarged il 
at their two ends (Fig. 8). The Rare 781 — 
last one is more pointed than the Fig. 8.—Caudal Vertebra, from near 
others and bears at its caudal end the caudal end of the tail. 
‘ . Fig. 9.—Fourth Caudal Vertebra, 
a small separate conical piece, ventral view. a, transverse processes; 
the rudiment of an additional] % cranial articular processes; c, hamal 
processes; @, chevron bone. 
vertebra. 
The parts of a typical vertebra—vertebral arch, transverse 
processes, cranial and caudal articular processes—may be 
recognized in the vertebre as far back as the eighth or ninth. 
The transverse processes (Fig. 9, a) are directed caudad and 
decrease rapidly in length. They are very small on the ninth 
vertebra, but may be recognized for a considerable distance 
back of this. The spinous process disappears at about the 
fourth caudal vertebra, and the vertebral canal becomes 
gradually smaller caudad, until on the eighth or ninth vertebra 
it becomes merely a groove open dorsad. 
Caudad of the third vertebra for a considerable distance, 
each centrum bears on each lateral face at its cranial end a 
short anterior transverse process, and on its ventral face at its 
cranial end a pair of rounded tubercles, hamal processes (c), 
which articulate with a small pyramidal chevron bone (d@) so 
as to enclose a canal. These structures disappear caudad. 
Cervical Vertebre. Vertebre cervicales (Fig. 10).—The 
cervical vertebrze number seven. The first two of these are so 
peculiar as to require a separate description, so that the last five 
may be first considered. 
Passing craniad from the fourth thoracic vertebra to the 
third cervical there is a gradual transition. The centra of the 
