This volume is not a book in any sense except the purely physical; it is a collection of unrelated papers whose only common feature is that they were presented by invitation at the 75th anniversary of the Sheppard and Enoch Pratt Hospital in Towson, Maryland. (Each of the authors except one has spent at least a year at this hospital at some time in his career.) The papers cover a wide range of subject matter; no specious attempts are made to relate them to each other; each paper is followed by a brief discussion. On the assumption that