On the Seasonal Change of Growth in a Reef Coral, Favia speciosa (Dana), and the Water-Temperature of the Japanese Seas During the Latest Geological Times

Abstract

During the previous year, a feature, which seemingly indicates seasonal changes of growth, was discovered in some Palaeozoic Tetracorals by the present author; this event lead him to examine numerous samples of recent as well as fossil corals, preserved in our Institute of Geology and Palaeontology, Tohoku Imperial University, Sendai. The same feature was also found in some Stromatoporoids, Tabulates and Bryozoa as well as fossil and recent Hexacorals. In these forms the vesicular or horizontal tissue is arranged in different densities at different heights above the base of the corallite; namely, a part of the corallite in this type is provided with minute, densely crowded and thickened dissepiments or vesicles, while the parts under- and over-lying it possess larger, less crowded and not thickened dissepiments or vesicles…..