240 ANATOMY OF THE ABDOMEN. 



THE SPLEEN. 



The spleen, or milt, is a viscus of a soft structure, but 

 without an excretory duct ; its colour is a reddish brown, 

 but both its hue and its size are variable. In shape it 

 resembles an acute triangle. Its texture is spongy, and 

 consists of erectile tissue ; it is so tender, that were it not 

 for its peritoneal covering, it would be liable to be torn by 

 the slightest cause. By its upper convex surface it is at- 

 tached to the left extremity of the stomach : inferiorly it 

 rests on the abdominal viscera. It is plentifully supplied 

 with bloodvessels, absorbents, and nerves ; particularly the 

 two former : but its use is altogether conjectural. It is 

 seldom idiopathically inflamed, although so eminently vas- 

 cular ; but its erectile tissue has subjected it to rupture, and 

 to a species of scirrhous enlargement : it has also been 

 found ossified to a considerable extent. 



THE RENAL CAPSULES. 



These are two irregularly-shaped bodies, situated each 

 in front of a kidney. Their size in the young subject is 

 very considerable, but lessens remarkably as age advances ; 

 internally they seem composed of two substances, one a 

 dirty yellow-coloured compact vascular part ; another more 

 pallid, less in quantity and more spongy in texture, from 

 which in the young colt a fluid may be pressed out. They 

 derive their blood generally from the emulgents, and occa- 

 sionally from the aorta ; their nerves are gained from the 

 renal plexus, but their functional purpose is wholly un- 

 known. 



THE KIDNEYS. 



The kidneys are two glandular bodies, situated in the 

 dorsal and the lumbar regions, at the superior part of the 

 abdomen ; the right being generally the most anterior ; the 

 left being pressed backward by the spleen. The kidney 

 bean, so named after these parts, serves to give a pretty 

 exact idea of their shape ; but which is by no means uni- 

 form in every horse. The central notch offers an entrance 

 to their vessels, and an outlet to their veins and ducts. They 

 are sustained in their situation by cellular investiture by their 



