146 



THE UHEST. 



arterial and the termination of the venous trunks and the col 

 lected vessels of the absorbents. The windpipe penetrates into 

 it, and the oesophagus traverses its whole extent. 



Most ingeniously and admirably is this whole structure con- 

 trived to fill its various purposes. 



The ribs are eighteen in number on either side. Nine of 

 them are perfect, and commonly called the true, or, more 

 properly, sternal ribs, extending from the spine to the sternum. 

 The remaining nine are posterior and shorter, and are only indi- 

 rectly connected with the sternum. 



The ribs- are united to the corresponetng vertebrae, or hones of 

 the spme, so as to form perfect joints — or, rather, each rib forms 

 two joints. Before the ribs reach the sternum, they terminate in a 

 cartilaginous prolongation. The cartilage is united to the ribs 

 and sternum by joints, and the cartilages of the posterior ribs 

 are united to them in the same manner. 



The sternum, or breast-bone, is a long, flat, spongy bone, form- 

 ing the floor of the chest. It supports the ribs by the connect- 

 ing cartilage. It is composed of from seven to nine pieces 

 united together by cartilage. The point of the breast-bone is 

 occasionally injured by blows, and has even been completely 

 broken ofi". A kind of tumor on it, difficult to heal, has also 

 been produced by some cruelty or violence. 



The front of the chest is a very important consideration in 

 the structure of the horse. It should be prominent and broad, 

 and full, and the sides of it well occupied. When the breast is 

 narrow, the chest has generally the same appearance : the 

 animal is flat-sided, the proper cavity of the chest is diminished, 

 and the stamina of the horse are materially diminished, although 

 "perhaps, his speed for short distances may not be affected. 

 When the chest is narrow, and the fore-legs are too close to- 

 gether, in addition to the want of bottom, they will interfere 

 with each other, and there will be wounds on the fetlocks, and 

 bruises below the knee. 



A chest too broad is not desirable, but a fleshy and a prominent 

 one ; )'et even this, perhaps, may require some explanation. 

 When the fore-legs appear to recede, and to shelter therhselves 

 under the body, there is a faulty position of the fore limbs, a 

 bend, or standing over, an unnatural lengthiness about the fore 

 parts ol' the breast, sadly disadvantageous in progression. 



The Intercostal Muscles. — The spaces between the ribs are 

 occupied by muscles firmly attached to their edges, the fibres ol 

 which cross each other in the form of the letter X. By the pro- 

 longation thus obtained, they have a much greater latitude of 

 action, than they would have if they run straight from rib to rib 



The ribs, while they protect the importani viscera of the tho- 



