132 EQUINE ANATOMY. 



SPLEEN. 



This is not properly an annexed gland of digestion, but from 

 its position it is discussed in this section. It has no duct and is 

 therefore, a ductless gland. 



It is situated in the diaphragmatic and left hypochondriac 

 regions, and suspended from the sub-lumbar. Its shape is falci- 

 form, and directed downward and backward. 



Weight, thirty-two ounces. 



It has an external convex face, an interiial concave, a convex 

 posterior and concave and sharp anterior border, a base or su- 

 perior extremity, and a point or inferior extremity. 



Ligaments. 



Suspensory, from sub-lumbar region and left kidney to base. 

 Gastro-splenic omentjim, a process of peritoneum enveloping 

 whole organ except at anterior fissure. 



Structure. 



Sej'ous coat, from peritoneum, most external. 



Fibrous coat, thick and strong, sending prolongations or trabe- 

 culae into the interior which support the splenic pulp. 



Splenic pulp, reddish material which fills the interior of the 

 organ ; composed of pigment, broken down corpuscles, etc. 



Malpighian coipuscles, small rounded bodies of lymphoid struc- 

 ture enveloped by the outer tunic of the small arteries. They 

 are large in well fed, and small in starved animals. 



Vessels. — Splenic. 



Nerves. — Solar plexus. 



THE PERITONEUM. 



The peritoneum is a serous membrane with a visceral and 

 parietal layer, and enveloping nearly all the organs of the abdom- 

 inal cavity more or less completely. 



Beginning at liver it forms the ligaments already described, a 

 fold, the gastro- hepatic omentum, which separates, to enclose the 

 stomach, and sending reflections to the duodenum and caecum on 

 the right, and the spleen on the left, forming iht gastro-splenic 

 omentum. Its median portion descends in front of the intestines, 

 having a large amount of fat developed in its structure, the great 



