The appendix does not, unfortunately, hang out from the surface of the body, where it could peacefully decay and drop off without prejudice to the rest of the body, or be quickly lopped off in the event of its giving trouble. On the contrary, it projects its stubby and insignificant length right into the midst of the most delicate and susceptible cavity of the body, the general cavity of the abdomen, or peritoneum. The thin, sensitive sheet of peritoneum which lines this cavity covers every fold and part of the food-tube, from the stomach down to the rectum. And when once infection or inflammation has occurred at any point in it, there is nothing to prevent its spreading like a prairie fire, all over the entire abdominal cavity from diaphragm to pelvis. If this wretched little remnant were a coil of explosive fuse within the brain-cavity itself, which any jar might set off, it could hardly be richer in possibilities of danger. A redeeming feature of appendicitis is that the appendix lies--so to speak--in a corner, or wide-mouthed pouch, of the great peritoneal cavity; and if the inflammation set up in it can be "walled off" from the rest of the peritoneal cavity, and limited strictly to this little corner or pouch, all will be well. This is what occurs in those cases of severe appendicitis which spontaneously recover. If, however, this disturbance bursts its barriers, and lights up an inflammation of the entire peritoneal cavity, then the result is likely to be a fatal one. Just how far nature can be trusted in each particular case to limit and stamp out the process in this manner is the core of the problem that confronts us, as attending physicians. In the majority of cases, fortunately, the peritoneal fire brigade acts promptly, pours out a wall of exudate, and locks up the appendix in a living prison, to fight out its own battles and sink or swim by itself. But unfortunately, in a minority of cases, by a wretched sort of "senatorial courtesy" which exists in the body, the appendix is given its ancestral or traditional rights and allowed to inflict its petty troubles upon the entire abdominal cavity, and include the body in its downfall. Lastly come the two most pertinent and appealing questions:-- What is the outlook for me if I should develop appendicitis? And what is to be done?