350 NAVIX ON THE HORSE. 



powerful muscles. Nothing adds more to the lofty appear- 

 ance of the horse than a well-formed, properly-arched neck. 



The dorsal vertehrce, or those of the back, are eighteen in 

 number. Like the vertebrae of the neck, they have lateral 

 or side processes, and superior or spinous processes. The 

 latter are very long, and particularly so where they form the 

 elevation called the withere. It is to these vertebrae that 

 the ribs are attached at what are called the articulating sur- 

 faces. 



The lumbar vertehrw occupy the region of the loins, or small 

 of the back ; they are six in number. They are larger and 

 heavier than the others, and have heavier but not so long 

 spinous processes. The sixth one articulates with the sacrum, 

 or rump-bone. 



The sacrum, or rump-bone, is a very thick, heavy bone, into 

 which the spinal canal enters and terminates. It is situated 

 between the last vertebra of the loins and the upper portions 

 of the two haunch-bones, being firmly united with all these 

 bones. It is very rough on its upper surface, having five em- 

 inences in line with, and corresponding to, the superior spinous 

 process of the true vertebra. To the side, and between these 

 eminences on each side, are four holes, through which the 

 terminating branches of the spinal cord pass out. The under 

 side of the bone is quite smooth. 



The bones of the tail are fifteen in number. They are nearly 

 round, and gradually decrease in size from the first until the 

 last. They are united by their flat ends to each other, and 

 the first to the sacrum by very clastic, fibrous cartiL^ge and 

 ligaments. They admit of very great freedom of motion, as a 

 sweep of the horse's tail in fly-time will show. 



BONES OF THE CHEST. 



The bones of the chest are the sternum, or breast-bone, and 

 ribs. The sternum is a single bone in the mature horse, and 

 the ribs are thirty-six in number, so that the number of bones 



