16 THE EXTERIOR OF THE HORSE 



and in tliose weakened by disease and poverty, the power of this muscle 

 is enfeebled, and the orifice becomes relaxed and loses its full power 

 of control. In paralysis of the anus the faeces are allowed to escape 

 from the bowel involuntarily. This condition is usually associated with 

 jDaralysis of the tail. 



The Perineum. — The perineum is the hairless region which in the 

 male extends from the anus to the scrotum, or purse. In the female it 

 is short, and limited below by the vulva. It is bounded on either side 

 by the thighs and buttocks. 



4. ANTERIOR EXTREMITY OF THE BODY 



The Breast. — The breast is situated at the lower extremity of the 

 neck, and in front of the chest, supported on either side by the arms. 

 In some horses it is fleshy and rounded, in others sharp and prominent. 

 Its basement structure is formed by the sternum or breast-bone. 



5. THE LATERAL AND INFERIOR REGION 



The Brisket. — The brisket is a prolongation of the breast backward, 

 between the fure-limbs and along the inferior fece of the trunk, where it 

 forms the floor of the chest. Behind the elbows it corresponds to the 

 '■ girth-place ". 



The Chest. — The chest is a spacious cavity occupying the anterior 

 third of the trunk, and containing within it the lungs, the heart, and the 

 great vessels proceeding to and from them, as well as the oesojjhagus, 

 a portion of the trachea, and some important nerves. 



The withers and back form together its upper boundary. Outwardly 

 on either side it is limited by the ribs, to which in front are connected 

 the shoulder and the arm. The floor is formed by the sternum or breast- 

 bone, and parts in relation with it, while in front and behind it is 

 bounded by the neck and the abdomen respectively, and separated from 

 the latter Ijy the diaphragm or midriff. 



The Abdomen. — The abdomen embraces all that region comprising 

 the inferior and lateral parts of the trunk between the chest in front and 

 the sheath and groin behind, or, in the female, the groin and the mammary 

 gland. It encloses the organs of digestion, urination, and generation, and 

 other accessory parts. Its outer and inferior walls are made up of super- 

 imposed layers of broad expanded muscles and their tendons, which are 

 braced up by a sheet of elastic tissue that spreads over the under surface 

 of tlie belly immediately beneath the skin. Within is a more or less 

 thick layer of fat. 



