SPLEEN. . 319 



near the superior surface of the gland, and is formed by two large 

 radicals, right and left, and in the horse it enters the duodenum 

 with the hepatic duct, in some cases uniting with the latter to 

 form the ductus comw.unis. There is sometimes, perhaps always, 

 an accessory canal {ductus pancreaticus minor) which enters the 

 intestine separately. The pancreatic secretion is clear and 

 colourless ; it mixes with the chyme, and assists in chylification 

 by emulsifying the fatty material, and so rendering the latter fit 

 for absorption. The pancreas is supplied chiefly by the hepatic 

 and anterior mesenteric arteries. Its nerves come from the solar 

 plexus. 



SPLEEN. 



The spleen is a soft, reddish-grey organ, situated on the left 

 side of the great curvature of the stomach, in the left hypochon- 



FlG. 108. 

 Internal aspect of the spleen, a, Superior extremity, or base ; 6, 

 Inferior extremity ; c, Internal surface ; d d, The hilus ; e, Anterior 

 border ; /, Posterior border ; g, Suspensory ligament. 



driac region. It is an exceedingly vascular, ductless gland, having 

 no excretory canal. In thft horse it varies in weight — from 

 about two to four pounds — and is shaped somewhat like a scythe 

 blade, the apex being directed obliquely downwards and forwards. 

 It has two surfaces, two borders, and two extremities. The 

 superior or external surface is somewhat flat, and is related with 

 the diaphragm ; while the inferior or internal is slightly concave, 

 and contacts the large colon. The posterior border is convex, 

 thin, and sharp ; the anterior thick," concave, and grooved by the' 

 splenic fissure, or hilus, in which lie nerves and vessels; the 

 gastro- splenic omentum is attached to this border. The base or 

 superior extremity, large, thick, and straight, is related to the 



