THE Tropical Biological Station, founded by the 1 Japan Society for the Promotion of Scientific Research, was opened officially in April 1936 with a staff consisting of a director and three researchers drawn from Japanese universities. Its laboratory is situated to the south of Kororu Island in lat. 7° 21' N., about the middle of the main Palao series. The whole group lies 500 miles east of the Philippines and consists of three or four small atolls to the north, a single elevated limestone island to the south and in the centre a great bank about 80 miles long by 15 miles broad with six main islands and more than two hundred islets. Most of the land is situated to the east with fringing reefs, while a great barrier to the west encloses a long narrow lagoon, which reaches a depth of more than thirty fathoms. Andesite and crystalline limestone form the land, the latter in terraces mainly in the southern half. Historically, the group is interesting for Karl Semper ("Animal Life", 1881), on the evidence collected there, was one of the first of that long series of field workers to dissociate himself from Darwin's theory of universal oceanic subsidence to explain the formation of atolls and barrier reefs.