Special Issue: Biological Pattern Formation Preface Y. Iwasa, H. Matsuda, A. Sasaki and T. Sekimura Forma, Vol. 12 (No. 2), p. 99, 1997 [Preface] Topology of Visual Cortical Maps Shigeru Tanaka Forma, Vol. 12 (No. 2), pp. 101-106, 1997 [Abstract] A Stochastic Model for Cell Sorting and Its Application Atsushi Mochizuki, Yasuhiko Takeda, Hiroyuki Ide and Yoh Iwasa Forma, Vol. 12 (No. 2), pp. 107-122, 1997 [Abstract] A Neural Network Modeling for Concentration-Dependent Pair-Rule Gene Expression Yasuhiko Takeda and Yoh Iwasa Forma, Vol. 12 (No. 2), pp. 123-142, 1997 [Abstract] The Plasticity in Shoot Morphology of Herbs in Relation to Light Capture by Leaves Toshio Sekimura Forma, Vol. 12 (No. 2), pp. 143-152, 1997 [Abstract] Coexistence States for Some Population Models with Nonlinear Cross-Diffusion Yoshio Yamada Forma, Vol. 12 (No. 2), pp. 153-166, 1997 [Abstract] Simulation Study of Stratified Diffusion Model Fugo Takasu, Kohkichi Kawasaki and Nanako Shigesada Forma, Vol. 12 (No. 2), pp. 167-175, 1997 [Abstract] Time Evolution of Space-Structure and Strategy for a Population Dynamics in the Lotka-Volterra Lattice Haruyuki Irie and Takao Bogaki Forma, Vol. 12 (No. 2), pp. 177-182, 1997 [Abstract]