Florence Margaret Durham

Between 1900 and 1910, Gregor Mendel's work on inheritance was rediscovered and caused a bitter controversy between its supporters – William Bateson and his group of Mendelians – and its opponents, who included Walter Frank Raphael Weldon (Bateson's former teacher) and Carl Pearson. Weldon's group were known as the Biometrics. William Bateson's group at Cambridge was very unusual for its time, in that it was made up mainly of women.[2][6] Florence Durham, Edith Rebecca "Becky" Saunders and Muriel Wheldale performed work to show that complex traits could be explained by Mendel's law of segregation. Florence´s sister Beatrice was also actively involved in his research.[7]

Florence Durham joined Bateson´s group as a post-graduate research student who had already published research.[1]

Durham began working on the heredity of mice coat colours in 1903, with Muriel Wheldale. She challenged the prevailing view of Lucien Cuénot, who proposed that it was the combination of factors which explained the different colours of mouse coats.[2] Beatrice Bateson wrote in her memoir that her sister Florence "hybridised mice in a kind of attic over the Museums".[2]

Durham invoked the concept of epistasis to explain that coat colour relied on the relationship between four different factors.[2] The term "epistasis" was coined by William Bateson, and Durham invoked it to explain how genes could interact in a more complex way than the simple dominant and recessive characteristics identified by Gregor Mendel. She wrote, "the terms 'dominant' and 'recessive' should only be applied to express relationship between factors in the same allelomorphic pair". She also undertook some chemical analysis of the pigments in mouse skin and hair in the Chemistry Department of Cambridge University with Gowland Hopkins.[2] She worked on several projects. In 1905 she began a collaboration with Dorothea Charlotte Edith Marrya on sex inheritance and eye colour in canaries. Their published observations in Durham and Marryat (1908) that pink eyes and female sex were inherited together in cinnamon canaries provided a possible mammalian example for sex linkage that had been recorded in moths. Durham continued working with canaries for at least the next decade.[2]

In 1906 she attended the Third International Conference on Genetics in London and attended a further international congress in 1911.[2] In 1910 she gave a lecture about 'Mendelism and the Laws of Heredity' to the Girton Natural Sciences Club, illustrated with mice that she had bred.[2] In 1910, she moved to the new John Innes Horticultural Institute in Surrey where Bateson had accepted a position as director to work with him on plant genetics, including a study of tetraploid primrose hybrids.[2]

From 1917 until her retirement in 1930, Durham worked for the Central Research Laboratory (now the National Institute for Medical Research), in its Division of Biochemistry and Pharmacology,[2][3] working under Henry Dale. Her work mainly focused on neosalvarsan, an organoarsenic compound that was used to treat syphilis. She and her colleague Miss Marchal were responsible for ensuring that preparations of neosalvarsan met the quality standard[8] and issuing licences on behalf of the Board of Trade.

In 1932, Durham published the results of a long-term experiment into the genetic effects of alcohol on guinea pigs, conducted at NIMR.[9] The study was done in response to reports by American researcher Charles Rupert Stockard that the offspring of alcohol-exposed guinea pigs exhibited defects attributable to the parents' alcohol exposure.[2][9] After breeding 6,983 guinea pigs over the course of several years, Durham found no evidence that daily doses of alcohol had any hereditary effects; the percentage of offspring born with genetic defects was no higher among the intoxicated guinea pigs than among the control group.[9] This was one of several studies that discredited the Lamarckian theory of inheritance that Stockard's work appeared to support.[9]