124 THE WORK OF THE DIGESTIVE GLANDS. 



lecture because its solution is intimately connected with previously 

 established relations. The experiments which concern the excitants 

 special to the pancreas are, as we have seen, very simple, but it is quite 

 otherwise with those agencies which are at the same time excitants of 

 gastric juice. They will naturally also be indirect excitants of the 

 pancreas through the acid of the latter. But this does not solve the 

 actual question in hand. It is necessary to determine whether they 

 are not also capable of acting independently and directly, apart from 

 the acidity of the gastric juice. And this, indeed, is not easy to 

 decide. 



Dr. Kuwschinski showed long ago that tempting a hungry dog with 

 food at times called forth a very lively secretion of pancreatic juice. 

 His conclusion, which was at that time perfectly justified, was that 

 the nerves of the pancreas can be excited by psychic influence, but this 

 obviously now requires further examination. Are we not dealing with 

 a stimulating effect of the gastric juice collected in the stomach under 

 the effect of the psychic impulse ? It was necessary to repeat the 

 experiment in a manner which eliminated the intervention of the 

 gastric juice. In the beginning we placed our hopes on a complicated 

 operative procedure. We performed cesophagotomy on a dog, and also 

 made both gastric and pancreatic fistula?. We then submitted the 

 dog to a sham feeding, with the gastric fistula open, and were able to 

 observe the onset or augmentation, as the case might be, of pancreatic 

 flow. The result, however, of this experiment is ambiguous. It would 

 have been decisive if no juice had flowed. Now, however, we may draw 

 divergent conclusions. It may be that, e/en with an open gastric 

 fistula, part of the juice obtained entry into the duodenum. But there 

 was another way by which the matter might be decided, viz., the deter- 

 mination of the latent period of sham feeding for the pancreas. The 

 latent period of the gastric secretion in dogs has a sharply marked lower 

 limit, and is never less than four and a half minutes. The pancreatic 

 juice, on the contrary, begins to flow two to three minutes after the 

 application of the exciting agency for example, an acid. In the experi- 

 ment of teasing the animal by offering it food, the pancreatic flow also 

 generally begins after two to three minutes. This appears to me to point 

 to a direct psychic influence through the secretory nerves of the pancreas, 

 such as has long been established for the secretory mechanism of 

 the stomach. And with this, probably, a phenomenon is connected, 

 which one may often notice when the flow of pancreatic juice is 

 observed in a fasting animal. After a rumbling sound in the abdomen 

 a more or less active secretion often sets in; the gastric glands, however, 

 remain in perfect rest. One is at liberty to conceive that a passing 

 desire for food has thrown the centres for the motor nerves of the intes- 



