This subject index, when used in conjunction with other published author and subject cumulative indexes and Mathematical Reviews Annual Indexes provides complete indexes for the entire run of MR from its beginning in 1940 through the present. This index includes listings for the reviews in 1959-1972 MR and is ordered by the subject classification scheme in effect during 1968-1972, with the 1962-1967 articles having been reclassified as necessary. Under each heading the subject index lists all items reviewed in MR with either primary or secondary classification in the given area. To locate a given item, this subject index may be used in conjunction with the appropriate author indexes which provide full bibliographic information as well as the reviewer's name.