NERVES OF THE PANCREAS. f>7 



At the present moment, however, the investigation of the nervous 

 relationships of these glands has greatly advanced. We have already 

 stated that Bernstein, in Ludwig's laboratory, and afterwards myself, 

 with Professor Afanassjew, have shown that sensory stimuli exert an 

 inhibitory influence on the pancreatic gland. Then Heidenhain, with 

 his pupil Landau,* from excitation of the medulla oblongata, obtained, 

 in a few experiments out of many fruitless ones, an undoubted effect 

 upon the gland. On the whole, however, the question of innervation 

 of the pancreas remained very obscure. Why could Heidenhain obtain 

 an effect only in exceptional cases ? By what channels were the 

 impulses conducted from the central nervous system to the gland ? To 

 what influences were the inhibitory effects of sensory stimuli to be 

 attributed ? There was as yet no answer to all these questions. 



Beginning with the year 1X87, it was the good fortune of myself 

 and my co-workers to be able to solve them all, more or less 

 satisfactorily. 



It resulted that the vagus is to be looked upon as the secretory nerve 

 of the pancreas. For this discovery we have to thank the adoption of 

 a special expei^imental procedure, and the method by which we were first 

 convinced of its activity will be immediately demonstrated to you. The 

 dog before you is provided with a permanent pancreatic fistula, made 

 in the manner I have described in the first lecture. The animal has 

 fully recovered from the operation and everything is healed. Four 

 days ago the cervical vagus was divided on one side ; the peripheral 

 end of the nerve was laid bare, furnished with a ligature, and preserved 

 under the skin. I now carefully remove the cutaneous sutures, and 

 cautiously draw forward the ligature with the nerve, without causing the 

 dog appreciable discomfort. I beg you to note that from the metallic 

 funnel, the wide end of which embraces the site on the abdominal 

 wall where the orifice of the pancreatic duct is situated, not a drop of 

 juice flows. Now I begin to excite the nerve with an induction current. 

 As you see, the dog remains perfectly still in its frame without 

 exhibiting the least degree of pain. Two minutes elapse without any 

 result from the stimulus this I ask you especially to bear in mind 

 and now, in the third minute, the first drop of juice makes its appearance, 

 and is followed by others in quicker and quicker succession. After three 

 minutes I interrupt the excitation, but the juice continues to flow 

 spontaneously, and only stops at the end of four to five minutes from the 

 cessation of the stimulus. I again apply the current, and obtain the 

 same effect, and this is invariably the result, upon evei-y dog. To this 

 must be added that the vagus nerve naturally was stimulated before, 



* Zur Physiologic d. Baitch&peichelabsonderiing. Rresltm. 1x7:!. 



