The anterior abdominal wall, including the anterior parietal peritoneum, is supplied by the lower six intercostal nerves, the last thoracic nerve, and the ilio-hypogastric and ilio-inguinal nerves from the first lumbar. It is a very interesting and important fact that, although the parietal peritoneum is exceedingly sensitive to touch and pain, the visceral peritoneum and the viscera themselves are insensitive. When operations are performed under local anæsthesia of the abdominal wall, the viscera can be freely handled or incised without the patient experiencing the slightest discomfort, provided that the parietal peritoneum is not put upon the stretch by traction on the mesentery or other peritoneal attachment. Thus the colon can be opened twenty-four or forty-eight hours after being brought outside the abdominal wall without any anæsthetic in the operation of colostomy. Local anæsthesia is therefore well adapted to cases in which a small amount of manipulation of the viscera is required, and where a general anæsthetic would be dangerous, as in grave cases of intestinal obstruction and in cases of carcinoma of the œsophagus with weakness and loss of flesh from starvation. GASTROSTOMY.--This operation is commonly performed under local anæsthesia and may be taken as an illustration of the procedure employed. The incision is made through the middle of the left rectus and is about two and a half or three inches long, beginning about an inch below the costal margin. An intradermal wheal is established at the middle of the proposed incision. A long needle is entered at this point and passed first upwards and then downwards in the line of the incision, infiltrating the subcutaneous fat as it goes. The needle is then passed in through the anterior wall of the rectus sheath, this being easily recognised as a plane of decided resistance. The needle is advanced a little inside the sheath, the injection being continued as it advances. The same procedure is repeated at various points along the line of the incision. The extra-peritoneal fat may be infiltrated in the same way, the posterior wall of the sheath being identified as a deeper plane of resistance and gently pierced. This step may be deferred until the posterior wall of the sheath has been exposed. The infiltration may be completed by forming a line of intradermal infiltration along the line of incision, though this last step can often be omitted. The abdomen can then be opened painlessly. The only step in the operation which may cause a little discomfort is the traction which may be necessary to bring the shrunken stomach down from under cover of the ribs. The incision into the stomach is quite painless. GASTRO-ENTEROSTOMY can be performed under local anæsthesia, the only special step required being infiltration of the meso-colon before it is perforated.