The material is presented as follows:

This section comprises letters received in Darlington's box-files of correspondence, or as loose papers. Other correspondence relating to Darlington's research, departments, publications, committees has been left with the related material elsewhere in the collection.

Although the correspondence includes letters from Darlington initiating or replying to correspondence, the majority of the letters are incoming only. However, many of them bear manuscript notes by Darlington either for a reply or of comment on points of interest to him, or - most frequently - underlinings and marginal markings, in red and blue pencil. Even relatively trivial communications may be illumined by reflections or comments of this kind, most of them in the characteristically pungent Darlington style.

The 'Lustige Blätter' is Darlington's own designation of two boxes of material, though sometimes he used the English 'Fun Box' and the plain 'Mad'. The material is extremely disparate. The majority are what appeared 'lustige' to Darlington, i.e. caught his fancy or made him laugh at the time.

The references and appointments are not available to researchers.