Lettice Digby was a British cytologist, botanist and malacologist. Her work provided the first demonstration that a fertile polyploidhybrid had formed between two cultivated plant species.
Education and personal life
She was born 31 July 1877 in Chelsea, London, UK. She was the second of the four children of Sir Kenelm Edward Digby and Hon. Caroline Strutt who had married on 30 August 1870. She studied at the Royal College of Science. By 1907 she was living in Kingsford, Colchester, and she died in Colchester, Essex, UK on 27 November 1972.
Scientific career
Digby was active in research within both botany and malacology, where she applied the technologies of cytology. Her application of cytology to the Kew primrose provided the first example of a polyploid hybrid to be recorded. This fertile polyploid species arose through chromosome doubling in an otherwise infertile hybrid. The fertile polyploid with 36 chromosomes was formed at Royal Botanic Gardens, Kew among infertile hybrids between P. verticillata, originating from Africa and Asia, and P. floribunda, from the Himalayas. The hybrids had been noticed in 1899 by staff at Kew, particularly Frank Garett, and were awarded a First Class certificate at a Royal Horticultural Society meeting in 1900. They were large plants with attractive flowers. The lack of fertile seeds despite repeated efforts at crossing the parents was a problem until some were obtained in 1905. Digby was thus able to compare both fertile and infertile hybrids. P. kewensis continued to be cited into the 21st century as an example of a new species originating from human activities. She made measurements of chromosome length, width and number during meiosis in both plants and animals such as Helix pomatia and Homarus gammarus. She collaborated with John B Farmer and John E S Moore, early investigators of the units of heredity. This included analysing the structure and taxonomy of some gastropods Moore had collected in Lake Tanganyika. This was at a time when the relationship of chromosome structures to inheritance was under active investigation. In addition, after the success of genetic studies in Drosophila, the selection of additional model organisms was needed to ascertain whether these findings could be generalised to all plants and animals. Smooth hawk's-beard was proposed as another model organism. Digby had studied its cytology, determining that it had 3 pairs of chromosomes. Her work on the structure of chromosomes, their changes during mitosis and meiosis and their relationship to the units of heredity was early support for the chromosome theory of inheritance. She spent some of her career at the Biological Laboratory, Royal College of Science and at the Jodrell Laboratory, Royal Botanic Gardens, Kew. During the First World War she spent time working as a laboratory assistant at the South African Military Hospital in Richmond Park, London. In 1919-1920 she was working with E.E. Glynn of University of Liverpool to study pneumococcal infections using serological and bacteriological methods, financed by the Medical Research Council.
