This Letter provides an extension of the earlier study on the interaction entropically induced between big bodies with a variety of shapes, large solutes, immersed in small spheres forming the solvent. The pattern of the aggregation of big bodies, which is strongly dependent on the big-body shapes, is discussed. Cases where the big-body shapes are changeable are newly analyzed. A possible mechanism of the amyloid fibril formation, which could be categorized as an ordered arrangement of large solute molecules occurring to increase the solvent entropy, is described. (C) 2004 Elsevier B.V. All rights reserved.