The collection contains notebooks covering Baker's undergraduate and research careers and notebooks relating to his biography of Abraham Trembley. Also included are miscellaneous notes, drafts and correspondence on scientific subjects, including the humane killing of crabs and lobsters. The most substantial series in the Additional Papers consists of correspondence and notes on anthropology and race, and includes draft chapters of the book eventually published as ...

The material in this collection includes notebooks on laboratory research, notes (both typed and handwritten) for lectures and practical classes, and a series of cytology notebooks.