On the Spiral Growth of the Inner Surface of the Calcitig Shell

In the preceding paper, the author has discussed the very important differences between the spiral growths of the aragonitic and calcitic shells, and suggested that a definite diffusion of the mother fluid existed on inner shell surface is favored by moving of the mantle in the direction of its own elongation, where concentration gradients assume to occur. Furthermore the differences between aragonitic and calcitic shells may have been due to those of the crystal system to which both the minerals belong. We can, however, hardly draw a certain conclusion at once, since we have no sufficient fundamental knowledges about the mineralization of molluscan shells on ecological and taxonomical points of view. In a series of biomineralogical studies on molluscan shells, the author would first try to take an abundance of observations on mineralization and development of shells.