56 PHYSIOLOGY AT THE FAKM. 



whole circumference of the arm ; but the less covered and more 

 fixed parts of the intestines resemble the arm bound close 

 to the side by a handkerchief passed tightly round the body. 



The duodenum is more capacious than the two other 

 divisions of the small intestines, though much shorter, and 

 yet its length is greater than its name denotes. The name 

 signifies 12 inches long, bearing reference to the same gut 

 in man ; in the horse the duodenum is about 24 inches 

 long. It begins in the pylorus at the right extremity of the 

 stomach. It makes a turn round the head of the pancreas, 

 having the liver before, and the great arch of the colon behind. 

 At the concave part of the liver it makes a sudden turn up- 

 wards and to the right, and obtains an attachment to the 

 right kidney ; it then crosses the spine between the roots of 

 the mesentery and the meso-colon to the left side, where it 

 forms the commencement of the jejunum. About six inches 

 from the pyloric orifice it receives at the same point the 

 pancreatic and hepatic ducts. The jejunum is extremely 

 tortuous, and being attached only to the mesentery, is per- 

 mitted to float loosely within the cavity. There is no 

 distinct line of division between the jejunum and the ilium, 

 the part named the ilium being one-fifth longer than that 

 named the jejunum. From the beginning of the duodenum 

 to the lower end of the ilium, there is a slight but gradual 

 tapering of the canal. The small intestines are estimated to 

 contain about eleven gallons of fluid. The small intestine 

 terminates in the side of the great intestine at a right angle, 

 and the part of the great intestine which forms the spur at the 

 point of entrance is that which is termed caecum, or the blind 

 gut that is, because it leads to no other cavity but its own. 

 The spur or projection which forms the csecum is between two 

 and three feet in length in the horse. 



The csecum of the horse has no appendix vermiformis like 



