MUSCLES OF THE TRUNK. 



309 



their inferior extremities or cartilages. The digitations forming the last inser- 

 tions do not intercross, in Solipeds, with those of the transversalis muscle of the 

 abdomen, being separated by an interval which is wider behind than before. 



Relations. — Anteriorly, it is covered by the pleura, and responds, mediately, 

 to the base of the lung. The posterior aspect, covered by the peritoneum, is in 

 contact with the greater part of the viscera contained in the abdominal cavity — 



Fig. 178. 



DIAPHRAGM OF THE HORSE (POSTERIOR FACE). 



1, 1', The two portions of the right crus or pillar; 2, left crus or pillar ; 3, tendons of the pillars; 

 4, 4', peripheral muscular portion ; 5, left leaflet of the aponeurotic portion ; 5, 5', right leaflet 

 of the same ; 6, posterior vena cava ; 7, oesophagus passing through the opening in the right 

 pillar ; 8, posterior aoi-ta between the two pillars ; 9, cartilaginous circle of the ribs ; 10, 11, 

 section of the psoas muscle ; 12, section of a lumbar vertebra; 13, section of the common mass; 

 14, retractor muscle of the last rib ; 15, xiphoid appendage of the sternum. 



the stomach, colon, spleen, and liver ; the latter is even attached to this surface 

 for a portion of its extent. 



On each side of the pillars, the circumference of the muscle forms an arch 

 which passes over the great and small psoas muscles. 



