Physiology of circulation in the architecture of Anura.

A functional relationship exists between the size of erythrocyte and size of capillary passage at metamorphosis. The shift in red cell a/b (major/minor axis) ratio in relation to the changes in cross-sectional capillary area is signficant. These changes have been worked out in thyroxine induced Rana cyanophlyctis tadpoles in comparison with untreated controls. The physiological aspects of phylogenetic origin in relation to ontogenesis of lymphatic sinuses are summed up. A further correlation between the narrowing of capillaries and the sprouting and spreading of lymph sinuses is postulated.