The first university textbook on plant physiology appearing in the Netherlands since 1942, when the same author was editor of a more extensive textbook on general botany. As it was impossible to prepare a new edition of the old textbook in a sufficiently short time, Professor Koningsberger has written this “Introduction to plant physiology” based upon his university lectures for first and second year students of biology. Now this introduction fulfills the urgent need for an up-to-date textbook at the elementary level. The first part contains different aspects of the structure and function of plant cells including a discussion of some colloid-chemical considerations that are of importance for the understanding of the submicroscopical structure of protoplasm.