PUNCTURE OF THE RUMEN. 



583 



suffocation threatens. In the case of cows and sheep even a pocket 

 knife can be used, should a trocar not be at hand. Round trocars 

 without side openings are almost exclusively used ; the largest, 

 having a diameter of half an inch, is used for oxen, and a somewhat 

 smaller one for sheep. 



dorsal 



if enlrat 



Fig. 415. — Vertical section of the ox's body, showing relative position of 



rumen and other organs. 



a. Lumbar muscles ; b, abdominal muscles ; c, glands ; e, portion of the 



pancreas. (After Ellenberger and Baum.) 



The seat of operation is the centre of the left flank, which becomes 

 very prominent in the tympanitic animal. In fixing the spot, one 

 imagines a line drawn forwards through the angle of the haunch 

 parallel with the vertebrae. In cattle the trocar is inserted on this 

 line about 4 to 6 inches, and in sheep about 2 to 2| inches, in front 

 of the angle of the haunch. As delay is often dangerous, there may 



