ANATOMY OF THF. HORSE. 9 



Of the dorsal vertebrse, the distinctions arc less numerous 

 and striking. 



The First Dorsal Vertebra has a cervico-dorsal confor- 

 mation, manifested in the form of the body, the length and 

 sharpness of the spinous process, the protuberance and single- 

 ness of the transverse processes, the breadth and direction of 

 the articular processes. 



The Second Dorsal Vertebra differs from the others 

 in the curvation of its spine backwards, against that of the 

 third ; and in the breadth and direction of its anterior articular 

 processes. 



The other dorsal vertebrse are distinguishable principally 

 from the comparative form and length of their spines. The 

 first spine is short compared to the second, and terminates in a 

 sharp apex; the second has a broader extremity, and in some 

 instances is bifid ; the succeeding grow broader, and more ob- 

 tuse at their ends until they assume a form similar to those of 

 the lumbar vertebrm. The fifth spine is generally the longest; 

 the 12th or 13th the first that assumes the lumbar character. 



M. Girard correctly observes, also, that the articular depres- 

 sions upon their bodies for the heads of the ribs are less deeply 

 marked as we proceed backwards. 



The Efghteenth Vertebra, and the seventeenth gene- 

 rally, have no articular surfaces upon their transverse processes, 

 but ivhole ones upon their bodies for the ribs. 



In the lumbar region, 



The First, Second, and Third have broader spines, and 

 their articular processes are nearer together; The Fourth 

 possesses a surface for articulation with the fifth on each trans- 

 verse process; The Fifth assumes somewhat of the character 

 of the first piece of the sacrum, and has four surfaces for arti- 

 culation on its transverse processes; two anteriorly, opposed to 

 those on the fourth ; two posteriorly, adapted to similar sur- 

 faces on the sacrum. 



general remarks on the vertebral chain. 



The Spine exhibits for consideration four surfaces and two 

 extremities. 



Surfaces — Extremely irregular, presenting various emi- 

 nences and projections, hollows, grooves, and foramina. 



Superior Surface — In the neck, broad and (from the absence 

 of spinous processes) preserving a general level ; the equality 

 being interrupted only, anteriorly, by the spinal crest of the 



