22 



64. The pastern bones correspond with those of the fore extremities, 

 both in name and number. The bones above the hock are the same 

 in the pig and dog ; the hock, however, consists of 7 pairs of bones in 

 these animals ; while each have 29 pairs of bones under the hock. The 

 skeleton of the Sheep is analogous to that of the Ox, both in number 

 and names of bones. (See Plate VII.) 



65. Having now briefly run over the skeleton, naming and classifying 

 the bones, and noting their situation, structure, and use, I shall next 

 refer to the study of joints and ligaments, or Arthrology. The 

 various bones of the body are held together by means of dense fibrous 

 structures called Ligaments, to form Joints, which are of three 

 classes; but, in descriptive anatomy, these are subdivided. 



66. We will only deal here with the three primary classes, viz. : — 

 Synarthrosis — immovable — such as the union of the bones in the 

 head. Amphiarthrosis — slightly movable — as between the bones 

 of the vertebrae. Diarthrosis — movable in any direction — as in the 

 hip, shoulder, knee, &c. 



67. Ligaments are composed mainly of white fibrous tissue, 

 some ligaments, however, are mostly of yellow elastic tissue. The 

 Ligamentum Nuchae, which supports the head and neck, is V 

 shaped, and extends from the top of the shoulder, or withers, to the 

 crown of the head, and consists of two layers, or plates. Ligaments 

 which hold the ends of bones together are termed capsular and 

 binding. The capsular ligaments are fibro-membranous bags or 

 sacks, which envelop both ends of the bones, and are lined by a 

 fine synovial membrane which secretes the Synovia, or Joint Oil, 

 by which the articulation is lubricated. The binding ligaments are 

 flattened or rounded bands running from the lower end of one bone 

 to the top of the succeeding bone, and when present at the sides of the 

 joint are called lateral ligaments ; but when found between the ends of 

 the bones in the joint they are called interosseous, and when they bind 

 down tendons passing over the joints, are named annular ligaments. 



68. Cartilage, or gristle, is a pale bluish-white, firm, elastic, glistening 

 substance, which is found adhering to the surface of bones, and 



