De beheersing van mutaties. Hugo de Vries’ Werdegang van fysioloog tot geneticus

Abstract

The control of mutations Hugo de Vries' transition from physiology to genetics The central question of this article is why Hugo de Vries left the field of mechanistic plant physiology and became a geneticist in the mid-1880s. It is argued that this change of course can only be properly understood if we take de Vries' views on the role of science in society into account. For de Vries, science had a dual role. Firstly, scientific knowledge "had a civilizing effect. The spread of knowledge was one of the principal means to uplift the individual's spiritual level and to increase his happiness. This -view of science as an instrument of civilization can be traced back to the early nineteenth century and was still en vogue in the second half of the century. Secondly, science derived its importance from the practical benefits society might reap from it. According to de Vries, scientists should never lose sight of practice; their ultimate aim should always be to provide solutions for the problems of society, and 'useless' lines of inquiry had to be abandoned. In his view of society, de Vries sided with the progressive liberals, who took an important part in contemporary debates on the reform of society, and de Vries' scientific views nicely fit in with his political stance. Against this background, de Vries' switch to genetics does not come as a complete surprise anymore; it can be shown to have been a natural outcome of his constant effort to contribute to the improvement of agriculture and horticulture. I argue that practice was also central to de Vries' genetics research. His ultimate aim was to be able to control the mutations of plant and animals and to produce useful varieties at will. Finally I suggest that an additional incentive for de Vries to abandon plant physiology may have been provided by his Amsterdam colleague J.H. van 't Hoff In the 1880s, van 't Hoff took up his studies of osmosis and of diluted solutions, thereby invading, as it were, the field which de Vries had until then considered as his own. This prompted de Vries to redefine his field of competence as a biologist.