Modern surgery through the use of local anesthesia has focused attention on the celiac plexus. At first, the chief concern was merely to develop a technic for making injections into this plexus which would permit the carrying out of certain major operations under local anesthesia. This led to the recording of new observations concerning its physiology. Relatively little attention has been paid, however, to the exact macroscopic and microscopic appearance of this region in the light of recent surgical experiences. Some of the disturbances referable to the duodenum and the pancreas which make their appearance after operations on the gallbladder and other abdominal operations require an exact anatomic knowledge of the celiac plexus for their proper understanding. So, too, attacks of abdominal pain simulating pain due to gallstones can be better differentiated from pancreatic, celiac and other types of medical and surgical pain, if one appreciates more fully the histologic