DIGESTION IN THE SMALL INTESTINE. 



399 



terior surface of the pancreas presents in the wound. The next step, and perhaps 

 the most difficult, is the finding of the duct, a proceeding rendered difficult not 

 only by the extreme shortness of the duct, but by its being surrounded by nu- 

 merous blood-vessels, which bleed very easily and which bridge over the duode- 

 num and the overlapping edge of the pancreas. By keeping the anterior surfaces 

 directed forward this difficulty is reduced to a minimum, since here the duct is 

 nearer the surface and is only surrounded by a few small blood-vessels, while on 

 the posterior surface the vessels are 

 very large, and it is just back of a 

 large bundle of vessels that the 

 duct enters the intestine. On 

 carefully pushing aside with a 

 blunt hook the overlapping edge 

 of the pancreas at the lower border 

 of the angle formed by the trans- 

 verse and vertical portions of this 

 gland, and about two centimeters 

 below the ductus choledochns, the 

 larger pancreatic duct is seen and 

 may be distinguished from the 

 blood-vessel by its larger size and 

 white color. The finding of the 

 duct may be facilitated by the fol- 

 lowing observations : Where the 

 vertical segment of the pancreas 

 leaves the duodenum there is al- 

 ways to be found a thick vein 

 passing from the intestine to the 

 pancreas. Above this the pan- 

 creas lies directly under the gut, 

 joined to it by numerous bundles 

 of veins. The opening of the duct 

 lies usually in the space between 

 the first two of these or between 

 the second and third. After the 

 duct has been isolated, a thread 

 should be passed around it and it 

 should be opened with a pair of 

 fine scissors; a small silver can- 

 nula, about five millimeters in 

 diameter and ten centimeters long, 

 may then be inserted and pushed 

 up to the first division of the duct, 

 tying it securely by the thread 

 previously passed around the duct. 

 To make the cannula still more 

 firm, a stitch maybe passed through 

 the serous coat of the intestine and 

 then the cannula fastened there 

 also. The duodenum and pan- 

 creas are then returned to the ab- 

 dominal cavity, retaining the ends 

 of the thread and the free end of 

 the cannula in the wound, which 

 is then closed by sutures, first 

 sewing together the muscles and then the skin. Upon withdrawing the stilette 

 from the cannula a few drops of colorless, limpid fluid escape, which flow more 

 rapidly when the animal makes any movement and which is strongly alkaline 

 (Figs. 158 and 159). The secretion may be collected by fastening a rubber bulb 

 furnished with a stop-cock to the cannula. The bulb should be first compressed 

 so as to be emptied of air, the stop-cock closed and connected with the cannula. 

 On opening the stop-cock the tendency of the bulb to expand draws the fluid out 

 of the ducts. Generally the fluid is secreted quite rapidly, and may be collected 



FIG. 157. PANCREAS OF THE PIGEON. (Bernard.) 



P, first -pancreas with its duct, V ; P' P", second pancreas 

 with two ducts, V V" ; H, biliary duct opening into the duode- 

 num, D, below the gizzard, G; ch and h, secondary biliary duct3 

 opening into the ascending portion of the duodenum ; F, liver ; 

 S, stomach; P P' P", pancreas; a, opening in duodenum show- 

 ing a probe, b, inserted into secondary biliary duct. 



