A demonstration that a hormone is concerned in external pancreatic secretion.

A dog with the tail of the pancreas transplanted under the skin, and a Thiry fistula of the jejunum was demonstrated. The continuous secretion of the pancreatic transplant was collected for two hours. It amounted to 0.4 cc. Normal twentieth hydrochloric acid was applied by perfusion to the mucosa of the Thiry fistula after washing it with warm 0.9 per cent salt solution. After a latent period of 5 minutes a copious flow of juice from the pancreatic transplant resulted, amounting to 0.5 cc. in twenty minutes.

This experiment clearly demonstrates that when dilute hydrochloric acid (from N/10 to N/20) is applied to the intestinal mucosa something (a hormone, we believe) is caused to enter the blood or lymph stream which excites the cells of the pancreas to form pancreatic juice.