Although the results of this study have been of a negative character, the conclusions that may be drawn from it have an important bearing on the true anatomical character of the islands.
1. Neither inanition nor the prolonged injection of secretin has any noteworthy effect upon the number, size, or structure of the islands of Langerhans in the dog's pancreas.
2. The islands of Langerhans in the guinea pig's pancreas are in no way altered in phlorizin diabetes.
3. The islands of Langerhans are not formed out of exhausted or degenerated acini, but develop from the ducts or acini with which they are often in direct continuity.