Child star Johnny Sheffield was the son of British actor Reginald Sheffield, himself a former juvenile performer (he played the title role in the 1913 cinemazation of David Copperfield). A wan, sickly infant, Johnny's health and physical stamina was beefed up by a strict exercise regimen supervised by his father. At age 7, Johnny co-starred in the original Broadway production of On Borrowed Time. This brought the young actor to the attention of the MGM casting department, which was looking for a suitably athletic child to play Boy in the studio's Tarzan pictures. Beginning with 1939's Tarzan Finds a Son, Sheffield played Boy in eight "Tarzan" programmers, remaining with the series when it shifted its base of operations from MGM to RKO. After a brief period of unemployment, the 17-year-old Sheffield was cast as the lead in Monogram's Bomba the Jungle Boy series, which endured for three years and twelve low-budget pictures. Sheffield decided to retire from acting in 1955. He sank his film earnings into real estate -- growing quite wealthy in the process -- and enrolled as a pre-med student at UCLA. When last heard from, Sheffield was living in happy retirement, overseeing his numerous real estate holdings. Johnny Sheffield's film credits should not be confused with those of British character actor John Sheffield.