268 EXPERIMENTAL PHARMACOLOGY 



its attachment to the duodenum begins. The large duct 

 (Fig. 245) opens into the intestine about one-half inch 

 above this attachment. To find the duct take a probe and 

 with great care gently dissect the anterior edge of the pan- 

 creas away from the wall of the intestine. The duct will be 

 found passing from the substance of the pancreas obliquely 

 downward and inward through the intestinal wall. Pass a 

 ligature beneath the duct as shown in Fig. 245 and then 

 open the duct in the substance of the bowel wall. Insert a 

 small cannula and tie it in with the ligature. Attach a short 

 rubber tube to the cannula and bring it outside the abdomen 

 which is now closed with hemo stats. 



Give another dose of coniine and see if you get any secre- 

 tion from the pancreas. Stimulate the vagi nerves and note 

 any effect on pancreatic secretion. Kill the animal with a 

 big dose of coniine. Immediately after death quickly open 

 the thorax, pick up the phrenic nerves and stimulate them 

 with a weak tetanizing current. Does the diaphragm con- 

 tract? What theories do vou know concerning the cause of 



V 



death under coniine (Cushny: Journal of Experimental 

 Medicine, i, 202) ? Dissect out the small duct of the pan- 

 creas. What is the innervation of the pancreas? How is 

 its secretion controlled? 



EXPERIMENT LIX. 

 Atropine. (Frog: Heart and Vagus Nerve.) 



1. Pith a frog and take a normal heart tracing showing 

 the effects of stimulating the vago-sympathetic nerve and 

 the crescent. Then while the drum is going pour two drops 

 of atropine sulphate solution (one cubic centimeter equals 

 one milligram) on the heart. After a few seconds stimulate 

 the vagus trunk again. What do you observe ? How do you 

 explain it? Now stimulate the crescent. What do you ob- 

 serve? How do you explain this? 



2. Cut out both of the frog's eyes. Examine the size 



