In the pages which follow it has been impossible to do more than epitomize our present-day knowledge of surgery, an early disavowal which is intended to save too frequent repetition of the advice to consult, as needed, other larger and more specialized works. The attempt here has been rather to build up a framework upon which the student and the investigator may build with such other material as they may later select from the quarries which are accessible to them. Hence it has been impossible to describe or even mention all the operations which have been devised to meet various indications. Preference has therefore been given to those which have best served the author in his personal experience. Because of the numerous interrelations between surgery and internal medicine, so called, I have not hesitated to insert paragraphs and even whole chapters on subjects hitherto omitted from the later works on surgery. To teach a student how to recognize nasopharyngeal adenoids, to appreciate the widespread harm they may cause and how to cope with them, and at the same time to leave him quite unfamiliar with their too frequent relation to the status lymphaticus and its dangers, and to omit in such a work all reference to the latter, is to put knowledge and instruments into his possession without teaching him how rightly to employ them. A case of exophthalmic goitre affords another equally apt illustration, as being one in which the physician and the surgeon should heartily co-operate. The surgeon and the physician have drifted too far apart. It is time that they met again in the presence of the pathologist. Such a group, when properly constituted, forms an almost invincible triumvirate. It has been said that “the resources of surgery are rarely successful when practised on the dying.” Throughout these pages the attempt has been made to impress the fact that delay, in many of the borderland cases, is dangerous, and, often fatal, and that it is not just to charge to surgery the blame for such a result due to the physician’s dilatoriness.