the heads of Monogram pulled out and revived their company. Into the 1950s, Republic and Monogram released films that tended to be roughly on par with the low end of the majors' output. Less sturdy Poverty Row concerns—with a penchant for grand sobriquets like Conquest, Empire, Imperial, Supreme Pictures and Peerless—continued to churn out dirt-cheap quickies. As the majors increased their B-level production and Republic and Monogram began to dominate Poverty Row, many of these smaller outfits folded by 1937. Hollywood studio feature film, average length, 1938 Joel Finler has analyzed the average length of feature film releases from the various Hollywood studios in 1938, which indicates the degree, to which, each emphasized the production of B films: The Big Five majors MGM—87.9 minutes Paramount—76.4 minutes 20th Century-Fox—75.3 minutes Warner Bros.—75.0 minutes RKO—74.1 minutes The Little Three majors United Artists—87.6 minutes Columbia—66.4 minutes Universal—66.4 minutes Poverty Row (top three of many) Grand National—63.6 minutes Republic—63.1 minutes Monogram—60.0 minutes Brian Taves estimates that half of the films produced by the eight majors in the 1930s were B movies. Calculating in the three hundred or so films made annually by the many Poverty Row firms, approximately 75 percent of Hollywood movies from the decade, more than four thousand pictures, are classifiable as B's. Outside of the highly standardized realm of the series picture, studio executives saw developmental opportunities in their B lines of production. In 1937, RKO production chief Sam Briskin described his company's B films as "a testing ground for new names, and experiments in story and treatment." Cowboys, dogs and detectives The western was by far the predominant B genre in both the 1930s and, to a somewhat lesser degree, the 1940s; for most of the Golden Age, westerns of every stripe accounted for 25 to 30 percent of all Hollywood feature production. Film historian Jon Tuska has argued that "the 'B' product of the Thirties—the Universal films with [Tom] Mix, [Ken] Maynard, and [Buck] Jones, the Columbia features with Buck Jones and Tim McCoy, the RKO George O'Brien series, the Republic westerns with John Wayne and the Three Mesquiteers...achieved a uniquely American perfection of the well-made story." At the far end of the industry, Poverty Row's Ajax put out films starring Harry Carey, then in his fifties. The Weiss outfit had the Range Rider series, the American Rough Rider series, and the Morton of the Mounted "northwest action thrillers"