Abstract
The appearance of anisotropic phase in the unipolar coacervations of tobacco mosaic virus or bentonite solutions are explained theoretically, and the recent theory of Onsager is confirmed. As has been emphasized already by Langmuir, the repulsive forces between solute molecules and the force arising from thermal agitation are decisive for the occurrence of the anisotropic phase. The critical concentrations where the anisotropic phase starts are explicitly determined for prolate and oblate spheroidal and also cylindrical solute molecules. It is found that the critical concentrations are all inversely proportional to the axial ratios, and therefore, it is explained why these critical concentrations are of the same order of magnitude in spite of the totally different characters of solute molecules