Molecular transport of substances in the presence or absence of
membranes is an ubiquitous phenomenon. Research workers from various
disciplines in the biological and phys- ical sciences are actively
pursuing problems of transport. One of the important questions arising
in numerous biological transport situations concerns the differentiation
between passive and active transport. The latter is a more complex
phenomenon involving metabolic processes, and the economy of thinking
requires that attempts to explain any transport pro- cess from passive
mechanisms should be carried as far as pos- sible before invoking more
complex mechanisms. A precise de- finition and circumscription of
passive transport processes is of crucial importance. The symposium on
"Passive permea- bility of cell membranes" was therefore devoted to
these pas- sive transport processes and this book presents the proceed-
ings of the conference. This symposium, a satellite symposium of the XXV
Inter- national Congress of Physiological Sciences at Munich, Ger- many,
on July 25-31, 1971, was organized by the Department of Physiology,
University of Nijmegen, Nijmegen, The Nether- lands. It was held at the
Hilton Hotel in Rotterdam on July 20-22, 1971. The meeting was made
possible by generous fi- nancial support from the Dutch Ministry of
Education and Science (Ministerie van Onderwijs en Wetenschappenl and
from Boehringer Mannheim N. V., Ciba N. V., Essex (Nederland) N. V.,
Gist-Brocades N. V., Hoffmann - La Roche N. V., Merck, Sharp and Dohme
Nederland N. V., N. V. Philips, and Unilever N.