The latter part of the book is devoted to the description, from the assistant's standpoint, of various operations, step by step. For this purpose there are selected for consider ation only those operations that are commonly performed, those that typify certain groups of operations, those that constitute important emergencies, and those that require special description. Manifestly the assistant's manipulations must depend, in large part at least, upon the operator's methods; but since the essential and the commonly adopted technics are de scribed it ought not to be difficult to modify them to suit the needs of individual cases.