we found a quantity of driftwood, lying just on the edge of the bank of coral slabs. Some of the trunks were very large, being fifty or sixty feet in length, and from two to three feet in diameter. — The locality in which these large trees are found, would show that there is at times a very great rise of the waters, which must submerge the islands altogether.” This account was botanically accurate and gives much valuable data with which to make comparisons. In 1964 the channel mentioned by Wilkes was no longer evident represented by a narrow area on the NE side behind which there occurs a low lagoon flat covered with Sesuvium, Portulaca and Eragrostis. In the latter half of the nineteenth century guano mining was carried out on Enderbury Island. According to Hutchinson (1950) about 100,000 tons were removed chiefly from the northern portion. Much of the low flat area around the lagoon and covered with stands of Sesuvium – Eragrostis were also mined probably lowering the soil level to hardpan. During the 1930's colonists were established on the island by the U.S. Department of the Interior. Attempted plant introductions were not successful. The estimated amount of guano taken from Enderbury Island does not seem compatible with the present numbers of nesting sea birds. The guano areas of the island are at the edge of a lagoon which has probably dried up, or, at least been closed off in the recent times. The discovery of recently deposited marine mollusks supports this contention. The bluefaced booby is the chief nester along the lagoon rim but the present population would need a very long period with maximum populations in order to deposit 30 cm. of guano (Hutchinson, 1950). It seems necessary to suppose a possible shift in waters of high productivity near Enderbury and a drop in the population of guano depositing bird populations. The other alternative is to suggest a shift in rainfall patterns and a subsequent dying out of a Pisonia type vegetation under which guano deposition seems to occur on many of the wet islands (Fosberg, 1957). No remnant population of Pisonia occurs on Enderbury Island but a comparably dry island (Malden) does have a few Pisonia which are adjacent to the large guano works on that island. Oceanographic research in the Phoenix Islands may help favor one or the other of the above suppositions. It seems highly probable that the genera Sula and Fregata were and are responsible for the deposition of guano soils on dry central Pacific atolls. The Tournefortia grove on the west side of the island supports nesting populations of Sula sula and Fregata minor. There was no evidence of a phosphatized layer forming underneath the thin litter layer. It is these species with Sula dactylatra and Fregata ariel which deposits layers of guano in open sites where accumulation is apparent on the basis of the individual organism. The influence of man has been relatively slight on Enderbury Island as regards the vegetation. The thick guano layers, however, point to a period in the natural development of the island when the vegetation may have been of a differing composition or to a change in the numbers of nesting seabirds on Enderbury Island. (Digitaria pacifica has naturalized over the sandy inner slopes of the island and appears to be colonizing such areas.) The guano layers originally mined on Enderbury may have been laid down under climatic and/or vegetation regimes which are no longer extant.