1 Department of Zoology, University of Toronto, Toronto, Ontario, Canada M5S 1A1
2 Zoologisches Institut, Universität Göttingen, D-3400, Göttingen, F.R.G.
Abstract:
1. 1.|We demonstrate using thermodynamic arguments that water loss through arthropod epicuticle is well described by a linear law relating water flux to transmembrane vapour pressure drop.
2. 2.|The relationship applies equally to systems where the liquid or vapour exist on either side of a membrane.
3. 3.|An earlier claim by some workers that water diffusion through arthropod epicuticle is proportional to chemical potential drop across the membrane is found to be theoretically unjustified.
4. 4.|Recent measurements with Periplaneta cuticle support the prediction that flux at a given temperature is proportional to the difference in vapour pressure.
Author Keywords: Insect cuticle; water permeability; vapour pressure difference; thermodynamics; transpiration; driving force; water loss