Info. on name from my mother, Rosemary Wykes Tisdall, niece of D.C.'s wife, Eula Lynn Wykes Chamberlain. She stayed with "Uncle Doc and Aunt Eula" in Oak Cliff on first moving there in 1942. (Rosemary is buried in this cemetery, also.)
Uncle Doc's original name was "Thomas Wright Chamberlain." However, by the time he and Eula married, he'd already legally changed his name to "Doctor Crume Chamberlain," after an actual M.D. friend of his by that name.
Apparently, he and Dr. Crume were together so much that his neighbors and other friends dubbed him "Doc," a nickname that stuck.
Uncle Doc decided that if that's what everyone was going to call him, he might as well have "Doctor Crume" as his legal name!