Jennings was so struck by the continued production of hereditarily diverse clones at conjugation, even after many successive inbreedings, that he undertook to examine the matter mathematically. As a result, general formulae for the results of diverse systems of mating were published in a series of papers between 1912 and 1917; these were one of the main seeds from which the whole field of mathematical genetics developed.
In 1924, Hennings published an article in Scientific Monthly on "Heredity and Environment" which was prescient for anticipating the double helix, and provocatively liberal for its comments on racial differences and American immigration policy. (The Scientific Monthly, Vol. 19, No. 3 (Sept., 1924), pp. 225-238)
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