The following paper deals with the biography of Louis Blaringhem (1878-1958), an earlier twentieth-century French biologist. He was initially sceptical as to the validity of the rediscovered laws of Mendel and put allegiance to the Lamarckian inheritance of acquired characters and de Vries’s theory of mutation. However, in the inter-war period Blaringhem became a staunch adept of Mendel and was one of the first professors to teach his genetics at the Sorbonne. He was also involved in applied science and especially worked in improving crops. The study of his biography offers the opportunity for a reassessment of the notion of a national scientific style; this debate relates to the introduction of Mendel’s theories in France, and the inherent tension between pure and applied science.