The papers in this series pertain to the estate of JBS Haldane and his wife, Helen Spurway Haldane. JBS Haldane died in 1964. Following Helen Haldane’s death in 1978, PM Bhargava and his wife, Manorama Bhargava, handled her estate and corresponded extensively with JBS Haldane's sister, Naomi Mitchison, and her grandson, Graeme J Mitchison. Included here are letters, notebooks, handwritten notes, share certificates, financial documents, JBS Haldane’s Last Will and Testament, Helen Haldane’s autopsy, and articles on the Haldanes by PM Bhargava and other researchers. Certain letters also pertain to the dispatch of JBS Haldane’s personal papers to his family in the United Kingdom. These are a combination of originals and facsimiles. This series includes one photographic print and a newspaper article announcing Helen Haldane's death. Note on subseries: The files within the Correspondence subseries have been organized based on the original order of subject-wise arrangement. Letters within each broad subject have been arranged alphabetically and then chronologically, except in special cases. Certain key documents, such as official records, were removed and kept in the Official Records subseries. The share certificates under the Official Records subseries are oversized and have not yet been boxed. The third subseries contains personal papers, possibly compiled by JBS Haldane himself. It includes a notebook, handwritten drafts of his last will and testament, and notes on his surgical history, along with correspondence. These drafts were written by JBS Haldane in November 1962, when he was preparing for an operation in London.