Subseries consists of subject files of correspondence (C/S = Correspondence/Subject). Most of these files were active up until Dr. Penfield's death and are largely grouped by subject. They may extend over a number of years but seem to indicate a continuing interest on the part of Dr. Penfield.

This series consists of most of Dr. Penfield's correspondence. The series is composed of three sub-series corresponding to Dr. Penfield's "Simple System." (C = Correspondence)

This series contains correspondence between Helen Kermott Penfield and Wilder Graves Penfield, as well as other friends and family between 1920 and 1932.

Sub-series consists of general correspondence, essentially inactive files kept for reference (C/G = Correspondence General).

Sub-series includes all of Dr. Penfield's "correspondence-domestic", or personal correspondence, which was taken from his office at the Montreal Neurological Institute. This sub-series includes material which Dr. Penfield had collected before arriving at McGill in 1928. In particular, it includes correspondence between Dr. Penfield and his wife, Helen Kermott Penfield.

Subseries consists of published accounts (articles or stories). (E/P = Events / Published)

This sub-series consists of records generated by Wilder Penfield as Director of the Montreal Neurological Institute. This consists primarily of correspondence and reports about teaching curricula, budgetary information, maintenance, staff concerns, and general university affairs created through his activities with the administration of McGill University (Deans of the Faculty of Medicine and the Faculty of Graduate Studies and Research, Office of the Comptroller/Bursar, Presidents of the University, etc.).