140 ORIGIN, INSERTION, AND USE 



communicates with nerves coming from the sympathetic of 

 the other side. 



From the loins, the sympathetic descends into the pelvis, 

 and takes its course along the side of the sacrum, and forms 

 five ganglia, corresponding to the sacral nerves ; it finally ter- 

 minates by forming a union with its fellow. 



ORIGIN, INSERTION, AND USE OF THE DIFFERENT 

 MUSCLES OF THE HORSE. 



TRAPEZIUS, 



Or triangular muscle, is in the region of the withers. 



Origin. — From the processes of several dorsal vertebras, 

 and from the fascia covering them. Its fleshy fibres pass over 

 the shoulder bone, and there unite in a tendon. 



Insertion. — Into the spine of the scapula. 



Use. — It elevates the shoulder blade, and inclines it 

 backward. 



LATISMUS DORSI. 



Origin. — By a broad expansion over the posterior part of 

 the back and loins. Its fleshy fibres appear upon a level with 

 the top of the shoulder bone, and converge, in their course 

 downwards and forwards, over the ribs, to which they are 

 loosely attached. 



Insertion. — Into the inner and upper part of the os 

 humeri. 



Use. — To draw that bone backwards and upwards. 



RHOMBOIDEUS BREVIS. 



Origin. — From the dorsal spines. In passing downwards 

 to the scapula, it unites with the longus. 



Insertion. — Into the costa of the shoulder bone. 

 Use. — To draw the shoulder bone directly upwards. 





