The circumstances of the missing biographer or why Watson didn't narrate these four Sherlock Holmes stories

The author provides arguments to explain why four of Arthur Conan Doyle's sixty stories about Sherlock Holmes were not narrated by Dr. Watson. The arguments relate to logical demands of the plot in the cases of the two stories told by an unidentified narrator. The two told by Holmes seem to demand Watson's absence because the final elucidation requires skill in cutaneous diagnosis; the presence of a medical man would have, or should have, relieved the dramatic tension of the mystery too soon. The Sherlock Holmes stories can provide delightful diversion as well as serve constantly to enhance our appreciation for highly alert and careful physical examination.