174 EQUINE ANATOMY. 



tween tlie pillars of the diapliragm, and in various 

 ways arrives towards the sixth dorsal vertebrae, where 

 it leaves the aorta, crosses the azjgos vein between the 

 axillary arteries, comes out of the chest and then ter- 

 minates with a dilation in the anterior vena cava at 

 the juncture of the two jugulars. 



Great lymphatic vein. — Confluent of the lymphat- 

 ics of the right leg, right half of the head, neck and 

 thorax. It opens at the junction of the jugulars by 

 one or two openings, alone or by anastomosing with 



the thoracic duct proper. 



NEUROLOGY. 



Six pairs of lumbar nerves, whose superior branches 

 ramify in the spinal muscles and integuments of the 

 lumbar region and haunch. The inferior ramify in 

 the abdominal muscles and the region of the flank. 

 The third pair furnishes three inguinal nerves — one in- 

 ternal, two external. 



Lumbar portion of the sympathetic. — Continuation 

 of the dorsal chain ; it has the same aspect, and lies 

 against the small psoas muscle, runs to the lumbo-sac- 

 ral joint, where it becomes the sacral portion. Its af- 

 ferent branches come from the lumbar pairs. Its 



