The correspondence is chiefly concerned with James Ramsay MacDonald's address (folios 52-53) for a Keir Hardie Memorial Service (folio 51).

Amelia Defries, author of ‘The interpreter: Geddes’ (London, 1927), was assistant to Patrick Geddes for several years, and was responsible for organising his lecture tours, exhibitions, etc. Her letters discuss this work and her own writing. There are also (folio 289) three undated articles by her, apparently unpublished, entitled 'Three weeks in Nova Scotia - an Impression', 'Where no millionaires are' and ‘The value of natural environment'.

Also included are letters to Anna Morton from other correspondents.

The principal subjects are financial and business affairs such as the purchasing of property by the Town and Gown Association. John Ross was responsible for organising many of Patrick Geddes's affairs. He helped with the Paris Exhibition of 1900, and assisted with gathering material for the Cities Exhibition in Madras in 1914, to replace that which was lost at sea.

The letters are chiefly written by Sir John Thomson to Patrick Geddes, 1883-1932. They discuss Thomson's career from study in Jena to collaboration with Geddes on writing biological works. Letters from 1924 to 1931 discuss plans for their joint work ‘Life: outlines of general biology’. The letters from Geddes to Thomson, particularly of 1924-5, contain numerous biological diagrams. There are also several letters from Thomson's wife to Anna Geddes discussing family affairs.

Most of the correspondence is concentrated around the years 1900-1901. The principal subjects discussed are the Paris Exhibition of 1900, and the Glasgow International Assembly of 1901. The question of Thomas Marr's retirement from the Outlook Tower arises and new prospects are considered. Later letters from Marr are written from the Scots College, Montpellier, of which he was the business manager.

Most of the letters are from Patrick Geddes to Mrs Cunningham, written after 1925 when she became secretary of the Outlook Tower. At the time Geddes was writing chiefly from Montpellier, describing his plans and work there. Mrs Cunningham's letters concern the business of the Outlook Tower.

Included are several letters of Lewis Mumford to Frank Mears and Victor Branford. The correspondence deals principally with Mumford's early work, particularly between the years 1922 and 1929. Enclosed with a letter of 1922 (folio 29) is an outline of his book ‘The story of utopias. There is also a typescript of an essay entitled 'Graphics' (folio 68). In later letters he discusses his books ‘Sticks and stones’ and ‘Herman Melville’.

Patrick Geddes’ works on the ‘Evolution of Sex’ and ‘Thought in Action’ are discussed, as are the League of Nations, 1923, and nationalism in the India of the 1920's. There are also a number of personal letters with many condolences on the deaths of Anna and Alasdair Geddes in 1917.

Also included are several photostats of letters, 1923-1924, between Geddes and his youngest son, Arthur, who was working in Santiniketan, Bengal, and a few letters, 1924-1926, from the Reverend Charles F Andrews, Vice President of Rabindranath Tagore's Institution, Santiniketan. Both Tagore and Jagadis Chadra Bose discuss their work. Bose, in particular, describes his research involving electric phenomena and plant response. He was founder of the Bose Research Institute in Calcutta.

Raymond Unwin's letters concern the Cities and Town Planning Exhibition and its possible visit to America. There is a typescript of an agreement between Joseph Fels, John Willis Slaughter and Marcel Hardy of 1912 (folio 190), by which Slaughter and Hardy were to become agents for Fels in the purchase of land for cultivation in Paraguay. A letter of Patrick Geddes to Mrs Fels, 1920 (folio 146), is published in part by Philip Mairet in ‘Pioneer of Sociology’, page 186.

Included in the correspondence of Patrick MacLeod is a letter from India of 1800 recounting the expedition to Agra with Sir James Craig. Other letters came from England, Gibraltar, and Sicily. There are also letters to Patrick from his sisters, Isabella Gregory, Annabella Petley, Jane MacLeod written shortly before her death in 1804, and one from Patrick to his youngest sister, Catherine, 1804-1806.