This study was prompted by the current interest in the so-called ulcerogenic tumors of the pancreas.1 Reported cases have led to the speculation that a hormone-like mechanism may arise in, or be closely related to, the non-β cells of the islets of Langerhans. A possibility that neural mechanisms, or neuroendocrine mechanisms, might be involved, seemed to require a restudy of the basic anatomy of the nerve endings in the pancreas.
Human autopsy material, studied after staining with silver albuminate and pyridine in the presence of electrolytically active copper (technique of Bodian2), suggested that fixation artefacts interfered with the study of fine nerve fibers. Dog pancreas was then studied after fixation by perfusion of the vascular system at the time of death. Formolsaline is used, and further fixation in formalin by immersion is done. In fresh human autopsy material the celiac axis was perfused with fixative and the