Tp VETERINAIIY SCIENCE 



PART I. 



ANATOMY OF THE HORSE. 



CHAPTER I. 



BONE. 



BONES are hard, yellowish-white, insensitive objects which 

 form the skeleton of animals. Living bone is bluish 

 pink, insensitive and elastic. On exposure to air it 

 becomes diseased and blackened, and is very sensitive and painful. 

 Bones are made up of two kinds of matter — animal, which 

 makes the bone tough and elastic, and earthy, which makes it 

 hard and brittle. In young animals the animal matter forms 

 one-half of the substance, which afterwards diminishes to one-third 

 as the animal advances in age. This is why we account for old 

 animals' bones being easier to fracture and harder to mend. 



COVERING OF BONE. 

 Bones are covered by a tough, fibrous, inelastic membrane 

 called periosteum, which can be seen on examining a bone of an 

 animal which has just died. The only exception we have to this 

 is at the joints where one bone articulates with another, and 

 where a tendon or muscle plays over a bone ; here we find its 

 place taken by articular cartilage. 



CONTENTS OF BONE. 

 We find in the extremities or near the ends of bones, red 

 marrow, while in the shaft we find white marrow. 



aASSES OF BONE. 

 Bones are classed as long, flat and irregular. Long bones 

 are found in the extremities or legs, and serve as levers for 

 travellini^ and pillars to support the body. Always remember, that 



