What was it that the rediscoverers of Mendel’s laws thought they had rediscovered, and, more generally, do those who spark off a scientific revolution grasp the importance of the moment? This question lay at the heart of a meeting organized in Paris to mark the centenary of the publication of the rediscovery of Mendel’s laws in the Comptes Rendus de l’Academie des Sciences (26 March 1900)1xSur la loi de disjonction des hybrides. De Vries, H. C. R. Acad. Sci. Paris. 1988; 30: 7See all References. Under the auspices of Nobel Prize winner Francois Jacob and the Academy secretary Francois Gros, historians of genetics as well as practising geneticists, met to investigate the structure of the formidable scientific revolution that forms the basis of 20th-century biology. Apart from the popular story of the long-neglected Mendel, the two main questions that were raised at the meeting were: why was mendelism rediscovered, and how did it become the science of ‘genetics’?One important point to note is that in the first decade after the rediscovery mendelism, under William Bateson’s guidance, was not yet genetics. Although they perceived the rediscovery of Mendel’s laws as a breakthrough, the three ‘rediscoverers’, De Vries, Correns and Tschermak did not regard themselves as ‘geneticists’ and their prejudices often led them to retard the development of the new science. In the years following the rediscovery, De Vries put forward his Mutationstheorie which he considered to be more important than Mendel’s laws. Tschermak remained a skilled commercial plant breeder, which illustrates that mendelism was considered to be interesting but not essential to agriculturists. He died in the 1960s in the belief that breeding was an art rather than a science. Correns was a mendelian geneticist with an interest in sex determination in plants, but he rapidly came up against the problem of non-nuclear inheritance. Following their initial fame, the three rediscoverers were swept aside by the new generation of geneticists.The contemporaries of De Vries, Correns and Tschermak also did not immediately grasp the importance of Mendel’s laws. Although the novel science was quickly adopted, it remained to a large extent trapped in the quarrels of the past. According to Daniel Alexandrov (St Petersburg), in Russia mendelism was opposed by the ‘moderns’ and favoured by the ‘conservatives’. Robert Olby (University of Pittsburgh) showed that, in the UK, the material and intellectual support for mendelism in the early years came from the lords and ladies of the Royal Horticultural Society, a group of hybrid orchid enthusiasts who hosted the first ‘genetics’ meeting in 1905, rather than from the academic darwinians and middle-class scholars of the Eugenics Education Society, who opposed the allegedly idealistic conception of ‘invisible factors’ (Phillip Sloan, Notre-Dame University, France).It was in the USA and northern Europe, as well as in some French agricultural colleges, that mendelism first received support from the world of agriculture, which, together with horticulture and animal breeding, provided a favourable socio-economic context for the reception of genetics2xMendel in America: theory and practice, 1900–1919. Paul, D.B. and Kimmelman, B. : 281–309See all References. The meeting addressed the opposing views of whether the adoption of genetics by agricultural research was a way of introducing capitalist profit into farming (Garland Allen, Washington University, St Louis, USA), or an effective tool for applied research that ultimately ended in the green revolution (Nils Roll-Hansen, Norway).Finally, it emerged that, irrespective of legend, economics played a role in genetics from the very beginning. Roger Wood (Manchester University, UK), in a joint paper with Vitezslav Orel (Mendelianum, Brno, Czech Republic), showed that Mendel’s work was anything but inspired amateurism. The abbott of his monastery, Cyrill Napp, was a wise administrator concerned with economic development in Moravia. He recognized the local sheep breeders’ interest in ‘what is inherited and how’ and adopted Mendel as a young student, sending him to university for training as an experimentalist3xSee all References(Fig. 1Fig. 1).Figure 1Sheep breeding and the origin of Mendelism ‘What is inherited and how?’ These words, uttered with some impatience at the 1837 meeting of the Brno Sheep Breeders’ Society, came from Cyrill Napp, abbot of the monastery to which Mendel would be admitted as a novice monk in 1843. A major inspiration for Napp came from Moravian breeds of Merino sheep. Napp was decisive in encouraging Mendel’s education in horticulture and mathematics at the university. This ‘prehistory of genetics’ will be presented in a book being published by Oxford Univ. Press3xSee all References.View Large Image | Download PowerPoint SlideThe proceedings of the meeting will form a special issue of the 2000 volume of the Comptes Rendus de l’Academie des Sciences. Information along with summaries of the talks are available on its website (http://www.biop7.jussieu.fr/1900Mendel/1900Mendelve.html