THE VISCERA OF THE ABDOMEN, OK BELLY. 69 



The Colon is the largest gut, containing as much as twelve 

 gallons, being more than the whole of the small intestines. This 

 gut commences at the blind head in which the ileum terminates: 

 it quickly assumes a great size, being larger than the stomach ; 

 it takes a course round the caecum, becomes considerably smaller, 

 then makes a sudden turn, after which it again enlarges. It 

 again diminishes, makes another turn, and ends in the rectum. 

 The first part of this intestine is formed into a number of folds, 

 by means of three longitudinal bands, which, being shorter than 

 the intestine, causes it to pucker up, and form internally a 

 number of cells, by which the food is retarded in its progress. 

 The second part of the gut has only two of these bands, and the 

 folds are much fewer in consequence. 



The Rectum is a straight gut, holding about three gallons. 

 It has no cells, and is only partially covered by peritoneum; 

 but its muscular coat is considerably stronger than the others, 

 and enables it, with the assistance of the abdominal muscles, to 

 expel the fteces. This gut terminates in the anus, which is kept 

 closed by means of a circular muscle, called the sphincter ani, 

 Avhich is always in actiouj except when the dung is being 

 expelled. The small intestines are about twenty-two yards in 

 length, and the large about eight. 



The LIVER, whose office it is to secrete or separate the 

 bile from the blood, is a gland, and the largest one in the body. 

 It is confined to the diaphragm, and kept in its situation by 

 strong portions of peritoneum, called its ligaments. It is divided 

 partially into three lobes, — the right, the left, and the middle, — of 

 which the former is the largest, and the latter the smallest ; 

 besides these there are two small lobes. Its figure, therefore, is 

 very irregular, and its colour between red and brown. It is 

 supplied with arteries for its nourishment, with their correspond- 

 ing veins, together with nerves and absorbents ; but, in addition 

 to these, there are some large veins which convey to the liver 

 black, impure blood, from Avhicli it secretes or separates the bile. 

 The bile, being thus secreted, is conveyed by means of the 

 hepatic duct to the duodenum, which it enters about six inches 

 from the stomach. INIan and most animals possess a gall bladder 

 for the reception of, and as a reservoir for, the bile ; but the 

 horse does not possess any, so that the bile is almost continually 

 being poured into the bowels. The reason of this peculiarity 

 is, that the horse in a state of nature is continually feeding ; 

 having a small stomach, it requires frequent replenishing, and, 

 consequently, there is a continual demand for bile. The ox, on 

 the other hand, fills his paunch, and then ceases to eat for some 

 time ; consequently, he requires a large supply of bile at par- 

 ticular periods, and this is afforded by means of a reservoir — the 



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