This book is addressed to all biologists seeking a review of the various
transport processes of minerals and organic substances in plants from
the level of cell organelles to the longer-distance movements in the
largest trees. It is directed toward students having had some elementary
physiol- ogy, but the attempt has been made to provide information of
interest on the frontiers of current research. Doing this
comprehensively, we wished to consider all of the points of view that
appeared to be important; on the other hand, space and time were
limited. Therefore, the presentation had to strike an intermediate
ground between the style of a textbook giving representative treatments
of selected problems and a comprehensive ref- erence book covering all
ramifications. The reader will notice that the pendulum will swing more
toward one and then to the other. We did not want to avoid, and we felt
it was not appropriate to neglect completely our own special research
interests, which led to some emphasis on certain subjects. The immediate
origin of the book is the Heidelberger Taschenbuch 125 (HTB 125)
Stofftransport der Pflanzen by U. L. (1973), which in turn was preceded
by an earlier work, Aktiver Transport: Kurzstreckentransport bei
Pflanzen Protoplasmatologia vol. VIII/7 b by U . L. (1969). At the Li-
verpool Workshop on Ion Transport in 1972 organized by W.