MUSCLES OF THE BODY, OR TRUNK. 369 



blade, and is attached, or fastened, to the upper and inside part 

 of this bone. It is the principal agent in sustaining the weight of 

 the animal. It is the seat of strain of the inside of the shoulder 

 Muscles of the Abdomen, or Belli/.~These are generally broad 

 and long muscles, extending from before backward, being at^ 

 tached to the ribs in front, and the back-bone and haunek- 

 bones behind. They form the walls of the abdomen, and 

 assist m drawing the hinder parts forward. They also com- 

 press the bowels and assist in expelling their contents. 



The diaphragm is a muscle which should be well understood. 

 It forms the partition wall between the chest and belly. It is 

 a broad, thin muscle of very great power. It is attached to 

 the cartilages of the last pair of long, or true, ribs, and to 

 those of all the short ribs, except the last, and to the back end, 

 or cartilage, of the breast-bone ; also, to the bones of the loins' 

 or lumbar vertebra3. It is the principal muscle concerned in 

 moving the walls of the chest in breathing. Hiccoughino- is a 

 spasmodic action of this muscle, and is a very dangerous- 

 symptom in disease. The lungs and heart lie in front of the 

 diaphragm, and the liver, stomach, and intestines behind it. 

 The gullet passes from before this muscle to the stomach be- 

 hind it. 



Muscles of the Fore Extremities, or Arm and Fore-leg.— TK\^, 

 IS one of the most important classes of muscles of the horse 

 On their size, shape, and action the usefulness of the horse to. 

 n great extent, depends. Their office is to effect the various 

 motions of the fore extremities. They are generally heavy 

 round, and long. Many of them have long, round tendons ' 

 passing down to the lower bones of the limbs. 



The antea spinatus occupies the space in the front part of the < 

 outer side of the shoulder-blade, in front of the hio-b rido-e- 

 dividing the bone. It is fastened to the space in which it lien's 

 and extends down, and is attached to the capsular ligament of 

 the shoulder-jomt. Its action is to extend, or straighten, the- 

 upper bone of the arm, or humerus 

 24 



