Pacific Islands Oceania

Flora.

In any general consideration of the flora of the islands it is necessary to distinguish between the rich vegetation of the fertile volcanic islands and the scanty vegetation of the low coral islands, especially of the atolls often only here and there raised ¶lightly above sea-level. Of the plants not purposely brought in by human agency most must have been introduced by the wind or by ocean currents or by migratory birds, from one or other of the shores surrounding the ocean. The large but buoyant fruits of the coconut palm and of the "screw pine" (Pandanus), ocean borne, found foothold on the coral rock barely raised over sea level, and became the predominant vegetation of the low lands; doubtless the fact that both were found to offer an important food supply for vegetarian natives led to their being extensively planted by human beings in rather more inland parts, and even, as in some of the New Hebrides, far up on the hillsides. On thp other hand, the wind-borne spores of mosses and ferns, the winged seeds of many shrubs and trees, and the bird-carried, compara tively large fruits of many other plants found favourable homes in the higher volcanic islands, especially on the most westward slopes, with the result that in time many slopes have acquired typical intertropical rain forests. It need hardly be said that there is no hard and fast line between the coastal and the moun tain vegetation of the high islands which are more or less fringed by level coastal tracts; an instructive study of the merging of coastal and mountain vegetation is found in Lilian Gibbs' "Montane Flora of Fiji" (Linn. Soc. Journ. Botany, xxxix., 19o9).

Marvellously beautiful as this original vegetation of the islands is, it must not be overlooked that the profusion of fruits, flowers and beautiful leaves now to be seen in the inhabited parts of the islands has not been brought about by natural means. The natives in their early migrations certainly carried with them not only food and other plants useful to them but also plants valued by them for ornament ; that is to say they grew them round their houses and used the flowers and leaves—especially such as are scented— lavishly in dressing themselves for their ceremonies. Still more have Europeans since their arrival in the islands been responsible for the introduction of non-native plants, both useful and orna mental ; a good illustration of this is to be found in the late J. H. Maidon's paper on the "Flora of Norfolk Island" (Proc. Linn. Soc. of New South Wales, Vol. xxviii., pp. 692-785 [1903D, in which is shown the extent to which the abundant natural vegeta tion of that island, as seen by Captain Cook, the earliest European visitor, and by other early visitors, has been almost smothered by the useful and ornamental plants introduced during the first half of the last century from Australia.

Fauna.

The indigenous land fauna is exceedingly poor in mammals, which are mainly represented by rats and bats. The pigs, so much treasured by the natives of the Solomon and New Hebrides islands, were supposed to have been introduced by Cap tain Cook, but it now seems more probable that they are descended from a Papuan form brought by the Melanesians in their south ward migration into the Pacific. Cattle and horses when first

introduced—certainly by the early navigators—seemed not to thrive under domestic conditions; but when, as has happened in some of the larger and more mountainous islands, they ran wild, they increased rapidly; and more recently, when suitable fodder plants were introduced for their benefit, they have thriven greatly even in a domestic state.

Birds are much more numerous than mammals, among the most important kinds being pigeons and doves, especially the fruit eating pigeons, responsible as these doubtless have been for the distribution of the fruits from which many of the island plants have originated. Birds of specialized form occur in several of the island groups ; Megapodes in the Solomon islands, the New Hebrides, Samoa and Tonga, as also in the Carolines and the Marianas. The remarkable Didunculus occurs in Samoa, and after the introduction of cats and rats, which preyed upon it, was compelled to change its habits from living on the ground to living in trees.

Insect life has been said to be fairly abundant but unequally distributed throughout the islands; as a matter of fact, except in the Solomon and Hawaiian islands, and more recently in the Fijian group, where the subject has been more particularly stud ied, little more than a general knowledge of the insect fauna is available.

The marine fauna of the area is much richer than that of the land. Fish are very abundant, especially in the lagoons of atolls, and form an important article of food for the natives, who are generally expert fishermen. The gorgeous colour of many of the species of fish is noticeable, as also the fact that the flesh of certain species of fish is poisonous at certain seasons of the year, but not at other times. Turtles are also abundant. Among marine mammals the dugong occurs in the northern parts of the area; and whales traverse the waters of the area at certain seasons of the year. In considering the marine fauna the remarkable pa/o/o or balolo should be mentioned. This annelid propagates its kind by rising to the surface of the sea and dividing itself ; but this happens only in certain places, chiefly in the Fijian and Samoan groups, and on just two days in each year, the dates of which can be accurately predicted. As both the annelid and the fish which gather to prey on it are appreciated by the natives as a specially delicate article of food, the occasions of the appearance of the balolo are regarded as very important festivals.

For an account of the inhabitants and their social life see arti cles on POLYNESIA, MELANESIA and MICRONESIA, as well as the separate articles on a few larger island groups, e.g., Fiji.

The subsequent sections of this article deal with the island groups in greater detail and in the order in which they have been already mentioned.