BONES: DISEASES AND ACCIDENTS. 



By V. T. Atkinson, V. S. 

 [Revised by John R. Mohler, V. M. D.] 



Some knowledge of the skeleton is advisable to facilitate the study 

 of diseases of bones and the accidental injuries to which they are 

 exposed. The skeleton of the adult ox is made up of the following 

 number of bones: 



Spinal column 45 



Head 28 



Chest, 27 



Shoulder 2 — 1 on each side. 



Arm - — Ion each side. 



Forearm 4 — 2 on each side. 



Forefoot 40 — 20 on each side. 



Pelvis 2 — Ion each side. 



Thigh 2 — 1 on each side. 



Leg 6 — .3 on each side. 



Hind foot 38— 19 on each side. 



Total 196 



Without attempting to burden the reader with the technical names 

 and a scientific classification of each, it appears desirable to describe 

 some of the characteristics of forms in general and of a few classes 

 into which they may be divided, leaving the special study of in- 

 dividual bones to the illustrations of the skeleton (PI. XXV), which 

 will serve better than a great deal of writing to fix in the mind of the 

 reader the location, relation, and function of each one. In early fetal 

 life the place of bone is supplied by temporary cartilage, which 

 gradually changes to bone. For convenience of study, bones may be 

 said to be composed of a form of dense connective tissue impreo-nated 

 with lime salts and to contain two elementary constituents — the 

 organic or animal and the inorganic or earthy. In young animals 

 the former predominates; with increasing years tlie relative propor- 

 tions of the two change, so that when advanced age is reached the 

 proportion of inorganic far exceeds the organic. The gradual change 

 with advancing years from organic to inorganic has tlie effect of 

 rendering the l)oiie harder and more brittle, and thoiigh it is stronger, 

 the reparative process is slower when injury does occur. 



The bones are nourished in two ways: First, from the outside 

 through their covering, called the periosteum — the thin, strong mem- 



202 



