This series includes some 10,000 letters, telegrams, postcards and other communications received by Russell and his immediate associates over the years 1897 to 1956. The letters are arranged alphabetically by correspondent and then chronologically for each correspondent, with corporate entries and cross reference cards as described for the outgoing correspondence. Russell's colleagues often sought his opinion of their work, and some 175 manuscripts are interspersed with the incoming letters. Folders of correspondence which contain one or more manuscripts are labeled on the right side "Manuscript enclosed with correspondence". At the same time, there is a 3 x 5 yellow card for each manuscript which lists its author, title, length, date, and location. The yellow cards are arranged alphabetically by author in a file stored in the manuscripts catalogue.