242 MANUAL OF MODERN FARRIERY 



of its radiated fibres, with the assistance of that of the 

 crura, the cordiform tendon is transformed to a plane 

 surface, and the dimensions of the chest from front to 

 back thereby considerably augmented. When this 

 muscle acts, in consequence of the shortening of its 

 fibres, it loses its convexity, as above stated, and the 

 chest being thereby enlarged as well as the lungs, 

 the air rushes in, and inspiration is performed. This 

 muscle also assists in the natural constant motion of 

 the bowels, and lends its powerful aid in expelling the 

 faeces and urine ; and in females, facilitates the birth of 

 the young animal. 



The membranes by which the diaphragm is 

 covered viz., the pleura in front and the peritoneum 

 behind are very liable to inflammatory attacks. In 

 many cases of disease of the lungs and bowels, the 

 diaphragm is inflamed ; and this is sometimes the 

 cause of the breathing of the horse being so much 

 affected during inflammation of the chest and abdo- 

 men. It is likewise concerned in coughing, yawning, 

 and sighing. Sometimes it is ruptured, occasioned by 

 any violent exertion. We are, however, unable to 

 give distinct indications of this condition. In cases 

 of small rupture some portion of the intestines in- 

 sinuates itself into it, and there becomes entangled, so 

 that an incurable obstruction is the consequence. In 

 the event of a large aperture, the intestines protrude 

 through it, and by pressing upon the heart totally 

 suppress respiration. 



The gullet passes through the diaphragm into the 

 stomach, and in which it terminates. See Plate vm, 



