Surgical intervention in spinal cord affections has been at all times a matter of hesitation on the part of surgeons. Results were so varied and indefinite that for a long time no conclusions could be drawn as to the necessity and probable outcome of operative treatment. Statistics were meager and their reliability doubted where favorable results were recorded. In this paper I shall deal mainly with the different types of injuries to the spine and spinal cord, and endeavor to bring out the important points in diagnosis and definite indications for surgical treatment in cases amenable to it. I also hope to be able to show that in certain cases patients should not be operated on, as the cases are absolutely hopeless from our histologic knowledge of spinal cord degeneration and regeneration. Of course, it goes without saying that the basis of all this work is a very thorough and