The main islands are of considerable elevation. The highest point of Ponape reaching some 3,00o ft. The remaining islands of the group are generally low coral islets. The climate is equable and moist, but the islands are subject to severe storms. The vege tation is tropical and luxuriant, much resembling that of the neigh bouring island groups particularly the Marianas. The fauna is likewise similar to that of the Marianas group. The natives are careful agriculturists and clever navigators. Copra is the chief export.
The Marshall group consists of a number of atolls ranged in two almost parallel lines which run from north-west to south east between 4° and 15° N. and 161° and 174° E. The north east line, with fifteen islands, is called Radak, and the other, num bering eighteen, Ralik. The islands are under Japanese mandate. Area (estimated) 16o sq.m. with a population of 433 Japanese, 10 foreigners and 9,868 natives. The most populous island is Majeru. The islands were probably visited by de Saavedra in 1529, Capt. Wallis touched the group in 1767, and in 1788 Cap tains Marshall and Gilbert explored it. They were annexed by Ger many in 1885-1886 and passed under Japanese mandate after the World War. The atolls rise but little above high water mark. The highest elevation occurs on the island of Likiep but is only 33 feet. The lagoon is scarcely more than 15o feet deep and is accessible through numerous breaks in the reef. The reef scarcely exceeds 600 ft. in width. The surface of the atolls is covered with sand except in a few places where by admixture of decayed vege tation it has been turned into soil. The climate is moist and hot, the mean temperature being 80.5°. Easterly winds prevail throughout the year. There is little change of seasons the highest temperature being in January and the lowest in July. Vegetation, on the whole, is very poor. There are many coco-nut palms, bread fruit trees (Artocarpus incisa), various kinds of bananas, yams and taro, and pandanus, of which the natives eat the seeds. From the bark of another plant they manufacture mats. There are few animals. Cattle do not thrive and even poultry are scarce. Pigs, cats, dogs and rats have been imported. There are a few pigeons and aquatic birds, butterflies and beetles. Crustacea and fish
abound on the reefs.
The chief island and administrative centre is Jaluit. Protestant (American) and Roman Catholic missions maintain coloured teachers on many of the islands. The chief products for export are copra, tortoise-shell, mother-of-pearl, sharks' fins and trepang. The plantations of coco-palm amount to 1,275 hectares.
The Gilbert islands, or as these are sometimes called, the Kings mill islands, a chain of coral atolls, carrying some 16 small and low islands, begin slightly north of the Equator and only a little west of the 18o meridian line. Area 166 sq.m. Pop. (1933) 27,313 of which only 87 were Europeans. The soil, mostly of coral sand, seems originally to have produced little other vegetation than coconut palms, "screw-pines" (Pandanus), and perhaps a few bread-fruit trees; but, by digging pits to catch the rain water, a giant form of tannia has been introduced by the natives. These few plants—together with the very rich produce of the sea—must have sufficed to support a very dense population of Polynesians. The islands were discovered by John Byron in 1765, Capts. Gilbert and Marshall visited them in 1788. The dense native population of these islands led to the introduction of many of their number to Hawaii as labourers in 1878-1884, but the ex periment was unsatisfactory. The islands were claimed as Pro tectorates by Britain in 1892 and annexed as part of the Gilbert and Ellice Islands Colony in 1915. British and American missions are at work.
Some 200 m. west of the Gilbert islands and a little south of the Equator, are the two remarkable islands of Ocean island (native name Banaba), six miles in circumference (pop. [1926] 2,062 [126 European, 471 Chinese besides Pacific islanders]) ; and Nauru (Pleasant island), area 5,936 acres (pop. [1926] 2,217 [117 Euro peans and 822 Chinese besides Pacific islanders]), both notable for their rich phosphate deposits. Unlike the Gilbert islands proper, these islands have been elevated, probably by volcanic ac tion, much above sea-level—the highest part in each being about 26o feet. Even this elevation has allowed a rather more varied natural vegetation than in the Gilbert islands; the natural condi tions have however been much altered.