Question: What television network did Donald Losby appear on in his role for a Rod Serling anthology series?

Context paragraphs:
Rod Serling's Devils and Demons: Rod Serling's Devils and Demons is an anthology of fantasy and horror stories edited by Rod Serling and ghost edited by Gordon R. Dickson.  It was first published by Bantam Books in 1967.  Most of the stories originally appeared in the magazines "Fantasy and Science Fiction", "The English Review", "New Budget", "Worlds of Tomorrow", "New York Herald", "Routledge’s Christmas Annual", "The Smart Set" and "The Civil and Military Gazette".

The Zero Hour (U.S. radio series): The Zero Hour (aka Hollywood Radio Theater) was a 1973–74 American radio drama anthology series hosted by Rod Serling.  With tales of mystery, adventure and suspense, the program aired in stereo for two seasons.  Some of the scripts were written by Serling.

Night Gallery (film): Night Gallery is a 1969 American made-for-television horror anthology film directed by Boris Sagal, Steven Spielberg and Barry Shear consisting of three supernatural tales that served as the pilot for the anthology series of the same name, written and hosted by Rod Serling.  The film starred Joan Crawford, Ossie Davis, Sam Jaffe, Richard Kiley, Roddy McDowall and Barry Sullivan, and was broadcast on NBC on November 8, 1969.

Medallion Theatre: Medallion Theatre, aka Chrysler Medallion Theatre, is a 30-minute American anthology series that aired on CBS from July 11, 1953 to April 3, 1954.  A total of thirty episodes aired live from New York.  Henry Fonda (in the premiere telecast "The Decision of Arrowsmith"), Claude Rains, and Janet Gaynor made their major television dramatic debuts on this series in various 1953 episodes.  Others guest stars included Helen Hayes, Charlton Heston, Ronald Reagan, Jack Lemmon, Rod Steiger, and Roddy McDowell.  Among its writers were Rod Serling and Robert Anderson.  Directors included Ralph Nelson, Don Medford, Robert Stevens, and Seymour Robbie.  The producer was William Spier.

Darkroom (TV series): Darkroom is an American television thriller anthology series produced by Universal Television which aired on ABC from November 27, 1981 to January 15, 1982.  As an anthology horror/thriller series it was similar in style to Rod Serling's "Night Gallery."  Each 60-minute episode featured two or more stories of varying length with a new story and a new cast, but each of the episode wraparound segments was hosted by James Coburn.  Among the performers who appeared on the series were Steve Allen, Esther Rolle, Helen Hunt, Claude Akins, Richard Anderson, Lawrence Hilton-Jacobs, Carole Cook, David Carradine, Billy Crystal, Pat Buttram, Brian Dennehy, Lawrence Pressman, Dub Taylor, Rue McClanahan, Lloyd Bochner, Ronny Cox, R. G. Armstrong, and June Lockhart.

The Doctor (TV series): The Doctor is a half-hour medical anthology series that aired Sunday evenings on the NBC television network from 1952-1953.  Hosted by Warner Anderson, the program revolved around emotional problems.  The show is notable for having Rod Serling as a writer and Charles Bronson as one of the anthology actors.  Other actors who appeared included Anne Jackson, Ernest Truex, Mildred Natwick, and Lee Marvin.

Center Stage (TV series): Center Stage is an American television anthology series that aired in 1954 on the American Broadcasting Company as a summer replacement for "The Motorola Television Hour".  It aired on the American Broadcasting Company (ABC) on alternate weeks from June 1, 1954 to September 21, 1954, swapping airings with the "U.S. Steel Hour".  The series was produced by Herbert Brodkin.  There were nine episodes, one of which was written by Rod Serling.  Among its stars were Walter Matthau, Charles Coburn, Lee Marvin, and Vivian Blaine.

The Twilight Zone: The Twilight Zone is an American television anthology series created by Rod Serling.  The episodes are in various genres, including psychological horror, fantasy, science fiction, suspense, and psychological thriller, often concluding with a macabre or unexpected twist, and usually with a moral.  A popular and critical success, it introduced many Americans to common science fiction and fantasy tropes.  The original series, shot entirely in black and white, ran on CBS for five seasons from 1959 to 1964.

Donald Losby: Donald A. Losby, Jr (born May 26, 1951 in San Francisco, California) is an American actor, known primarily for his many character roles in popular television during the 1950s and 1960s in programs such as "The Adventures of Ozzie and Harriet", "The Andy Griffith Show", "The Twilight Zone", "Bonanza", "Rawhide", "Route 66", "The Fugitive", "Ben Casey", "Lassie", "My Three Sons", "Gunsmoke", "Daniel Boone", "Blue Light", "Lost in Space", and "The Young Rebels", as well as a small number of movies, typically playing the role of someone's son.

Night Gallery: Night Gallery is an American anthology series that aired on NBC from 1969 to 1973, featuring stories of horror and the macabre.  Rod Serling, who had gained fame from an earlier series, "The Twilight Zone", served both as the on-air host of "Night Gallery" and as a major contributor of scripts, although he did not have the same control of content and tone as he had on "The Twilight Zone".  Serling viewed "Night Gallery" as a logical extension of "The Twilight Zone", but while both series shared an interest in thought-provoking dark fantasy, more of "Zone"' s offerings were science fiction while "Night Gallery" focused on horrors of the supernatural.

Supporting paragraphs: Donald Losby The Twilight Zone
Answer: CBS