Data were collected on the careers of 10,000 holders of research degrees (PhDs, ScDs, and EdDs), via questionnaire, for a second study of PhD holders from the graduating classes of 1935, 1940, 1945, 1950, 1955, and 1960. The careers were systematically selected to represent a cross section of PhDs, and categorized into 4 groups: those always in academic employment, those shifting from academic to nonacademic jobs, those shifting from nonacademic to academic jobs, and those always in nonacademic positions. The report investigates career patterns in detail and illuminates factors related to a shift from academic to nonacademic employment or vice versa. Emphasis is placed on the categories of employers of PhDs and on factors related to change from 1 employer category to another. Some findings reveal that 50% of the PhDs spent their careers entirely in academic employment, 25% in nonacademic positions, and the remaining 25% were equally divided between those who shifted from academic to nonacademic jobs or vice versa. Annual rates of salary increase were typically about 8% for those always in or switching to academic work, higher rates were earned by those always in nonacademic work, while those shifting to nonacademic jobs were apt to receive an increase of almost 14% per annum. New PhDs, particularly those in the physical sciences, started on a higher academic level and advanced more rapidly than did their predecessors. (WM)