ABSTRACT
In both terrestrial and aquatic animals, a somewhat similar set of processes operates. Uptake through lungs, gills, oxygen uptake surfaces, or the gastrointestinal tract is followed by the establishment of an equilibrium with the circulatory fluid, which in turn, equilibrates with body lipids. In many cases, the equilibria are between similar lipoid material in different phases, for example, between circulatory fluid and body lipids. In other cases, the equilibrium is between an aqueous and a lipoid phase, such as that between ambient water and aquatic organism lipid. These equilibria can provide the basis for quantitative investigation of bioaccumulation. Equilibrium between the plant lipids and the external water or atmosphere can probably be established, given a sufficient time period. A particular area requiring similar investigation is the nature of the equilibrium between the contents of the gastrointestinal tract and the circulatory fluid and body lipids.
