400 



PHYSIOLOGY OP THE DOMESTIC ANIMALS. 



for several hours. After the first day, however, the character of the secretion 

 alters and is no longer normal or suitable for study. If it does not flow rapidly, 

 it may be stimulated by injecting ether through a tube into the stomach. Vom- 

 iting stops the secretion. Usually after the second day the tube and threads 

 drop out, or else they may be gently removed, and the wound generally heals 

 readily and the duct becomes restored. The same animal may again be used for 

 the same purpose. One of the difficulties that will be met with in this operation 

 is that, since the duct is so short, the cannula is very apt to slip out. This may 

 be partially remedied by having a cannula made with a little bulb on the end to 

 be inserted, or a T-shaped cannula may be used, the duodenal end of which must 

 be closed. If such a cannula is used it is better to have one made in two sec- 

 tions, one being first inserted in the duct and the other, which is to come out of 

 the wound, screwed in afterward. 



In the ruminant animal the pancreas lies in part on the convolutions of the 

 colon, on the superior right portion of the rumen, extending over the fissure of the 

 liver to the second lumbar vertebra. Its duct, six, eight, or nine millimeters in 

 diameter, opens into the duodenum in the ox eighty to ninety-five centimeters 



% V 



Fig. 158.— Pancreatic Fistula in the Doq. (.Bernard.) 



A, principal pancreatic duct: a, entrance of the duct into the intestine ; al, lesser pancreatic duct; 

 all, ligature fastening the cannula to the intestinal wall ; //, ends of the ligature ; I, duodenum ; P PI, 

 pancreas ; T, cannula ; V, rubber bulb ; B, stop-cock. 



below the pylorus, and in the sheep and goat at the opening of the bile-duct, and 

 is often free from gland-tissue for a space of from two to three centimeters. To 

 make a pancreatic fistula in the ruminant, an incision about ten to twelve centi- 

 meters long is made in the right flank parallel to the last rib and three or four 

 fingers' breadths removed from it. The pancreas then comes into view on open- 

 ing the abdomen, the duct may be readily exposed, and the cannula inserted. The 

 operation may be readily performed on the ox without uncovering the duodenum 

 frcto its omentum, and without dragging on the pancreas (Fig. 160). 



In solipedes it is difficult to study the pancreatic secretion . The gland is 

 deeply situated against the vertebral column, its duct is surrounded by gland- 

 tissue up to its insertion in the duodenum, and it has very thin walls. To make 

 a fistula it is necessary to freely open the abdominal cavity in the median line 

 from the sternum almost to the pubis, to withdraw the colon from the abdomen, 

 open the duodenum and insert a tube through the opening of the pancreatic duct 

 and fasten it by a ligature, which must also include part of the gland. The colon 

 and duodenum are then to be replaced and the wound sewed up. This method 



