Hugo de Vries and the plasmolysis method

Several authors (e.g. Faasse 1994) have noted that during the first half of the 19th century, plant science in The Netherlands was limited to visual investigation and classification. In the course of the century this descriptive approach was enhanced by the use of the microscope, by which inner structures could be added as tools for this floristic approach. The chairs in botany at the universities reflected this atmosphere. Outside the academic establishment plant science was practiced only by pharmacists and physicians, and the general knowledge about processes which are vital to living organisms was practically absent. This is illustrated by the fact that the foundation of a Society of Dutch Botanists in 1845 (the present Royal Botanical Society of The Netherlands) was the work of a small number of physicians and had as its goal ‘to stimulate and expand on scientific research of the native vegetation, in order to realize from its results the publication of a Flora of The Netherlands, which answers the contemporary demands of knowledge of the botanical sciences’ (Faasse 1994). However, in those days the educated public was apparently not excited by this typical floristic approach, since the society led an obscure existence. This changed only in 1871 when it started to organize meetings in which topics of general interest, including physiological issues, were discussed. This indicates that in the course of the century the time had come for a more comprehensive approach of plants, even for the general public. A strong stimulus to modernizing plant science in those days was the Higher Education Act of 1876, which resulted in a considerable expansion of the Dutch universities. Hugo de Vries, appointed in 1877 as reader and soon afterwards as professor in plant physiology at the University of Amsterdam, was the first Dutch professor in botany without a medical qualification. His appointment resulted in the separation of the systematic/morphological and physiological direction of plant science. From then onwards, plant physiology was treated as a separate discipline, founded on physics and chemistry and with a strong practical orientation, which was appreciated by the public and by the government.