yields to the course of Nature, decomposes, and adds to the previous soil. Seeds of other vegetables are wafted by the winds, or dropped by birds; and thus the bare rock, after a series of ages, becomes green with vegetation. Christmas Island, in the South Seas, is composed of sand, rotten vegetables, dung of birds, decayed shells, broken coral stones, and other marine productions. There is no fresh water; and therefore no inhabitants: but there are marine birds, land crabs, and lizards. The two clusters of islands, lately discovered, are but now emerging, as it were, into visible existence. They are so low, that they can be seen from the deck, even in the day time, only when ships are very They were discovered by De Peyster, while sailing from Valparaiso to the East Indies. To the former cluster he gave the name of Ellice's Group; to the latter, that of De Peyster's Islands. They were totally uninhabited. Byron and Wallis had previously borne down near these islands; but, from their lowness, they did not discover them. near. Some suppose, that land is entirely derived from the exuvia of marine animals. That the earth possesses a renovating power is certain. Islands expand, and become elevated by the combined influence of heat and water. The power, which heat possesses, of dilating bodies, arises out of its faculty of forcing itself between their separate particles. This, as a natural consequence, causes them to occupy a larger space than before. THE MANNER IN WHICH ISLANDS ARE FIRST PLANTED; AND BECOME PEOPLED WITH ANIMALS. THE manner in which distant islands become planted with vegetation is exceedingly curious. The Pacific Islands afford instances, from which the various methods may be success a May 17th, 1819-long. 180° 54′ W., lat. 8° 29′ S.-long. 181° 43′ W., lat. 8° 5' S. fully developed. How European and American fruits came to be naturalized in some of those islands is sufficiently obvious. Some have been carried thither by accident; some for delight; and others for subsistence. Some have been mixed with other seeds; and thus been transported against the will and wish of the transporters; as darnel amongst rye, and melilot amongst wheat. Cook planted the pine-apple and melon in Eoha; on Christmas Island yams and cocoas; on Lefooga melons, pumpkins, and Indian corn. Vancouver planted water-cresses and vine-cuttings in New Holland; on the Island of Cocos peas, beans, apples, melons, and peach-stones. Captain Colneth had previously left a variety of garden-seeds. On other islands he had also introduced the almond. Wilson planted the bread-fruit tree on the Palmerstone Islands. In Otaheite successive navigators have introduced various species of plants and vegetables and other islands have been benefited in a similar manner. But as the mode, in which these islands became rich in what we now call native plants, is a subject of some difficulty, we will assist in the endeavour to explain it. One of the circumstances, on which Columbus and his crew founded their hopes of being near land, was that of the Nigna taking up a branch, the red berries of which were as fresh, as if they had been taken immediately from the tree. Philips, also, in his voyage to Botany Bay, saw a great number of cocoa-nuts, floating at a great distance from shore b; and Captain Tuckey found several floating patches of reeds and trees, forty leagues from the African coast. Near one of the Aleutian Islands Captain Kotzebue picked up the log of a camphor-tree; and fell in with an iceberg, having a portion с a This tree, so abundant in its useful qualities, is yet held in little esteem in the islands of India.-Crawford's Indian Archipelago, i. 413. b Near Cape Musseldom the Indians throw cocoa-nuts, flowers, and fruits into the sea, to ensure a quick passage, and a safe voyage. Narrative, p. 55, 4to. of its surface lined with earth; in which grew trees and other vegetable substances". These, on From the The Canadians had formerly a custom of planting large trees on the ice. These remained the whole winter; and being evergreen, "you frequently appear," says Aubery, "to be travelling through an avenue of pines." the melting of the snow, float down to the sea. western shores, also, of America pines float to the Pacific Islands; an instance of which is afforded by the circumstance of two large canoes having been made of pine at Mowee and Attowai. The pine, as a living tree, is unknown in those islands. Indeed the American rivers, both north and south, during the time of their respective inundations, carry an inconceivable quantity of logs, weeds, shrubs, and other plants, down to the ocean. Large trees, too, of American growth are frequently picked up on the beach in the Azores. On the same coast, previous to the time of Columbus, a new continent and a new race of men were indicated by the appearance of a bamboo, and two dead bodies, having features and complexions widely differing from those of any men, at that time known. After violent storms cocoa-nuts are picked up on the beach of the North Seas. On the Shetland and Orkney Islands are occasionally thrown up fruits, belonging to the torrid hemisphere of America; on the shores of the Hebrides seeds from Jamaica; and on those of Ferro and Gomera, plants from St. Domingo. Seeds, cast on the coasts of Ireland and Norway, will sometimes take root and flourish. * The only insect seen by Captain Parry, in the higher arctic regions, was the Aphis borealis, which he found on floating floes of ice in the Polar Sea, and as far north as 8230. "Its near resemblance to Aphis picea, which feeds on the silver fir, would induce the belief, that the floating trees of fir, that are to be found so abundantly on the shores and to the north of Spitzbergen, might be the means by which this insect was transported to the northern regions." P. 201, 4to. b Trav. i. p. 208. c Munorz. Hist. del Nuevo Mundo, 1. ii. ss. 14. d Linnæus.-Coloniæ Plant. p. 3.-Amœnitat. Academ. 1. viii, Darwin alludes to these emigrations in the following manner : Where vast Ontario rolls his brineless tides, Some plants float from one end of the globe to the other. The trumpet-grass, seen off the Cape, is torn, for the most part, from the South African shores; but others are wafted from the American continent. The pistia straliotes float on pools, ditches, and rivers in Java. Its root takes but little or no hold of the ground. The marine weeds, that compose the grassy sea in the Atlantic, have neither roots nor fibres 2. They vegetate, as they float along, bearing green and red berries, harbouring a multitude of insects. There is also a plant in Chilib, and a similar one in Japan, called the "flower of the air." This appellation is given to it, because it has no root, and is never fixed to the earth. twines round a dry tree, or sterile rock. Each shoot produces two or three flowers like a lily; white, transparent, and odoriferous. It is capable of being transported two or three hundred leagues; and it vegetates as it travels, suspended on a twig. It Many plants have a double faculty of propagation. The testuca ovina has this property. When it grows in a vale, or upon a plain, its seeds ripen, fall, and vegetate in the manner of other plants. But when it grows upon the tops of mountains, where it finds a difficulty in ripening its seeds, it becomes a viviparous plant. The germ shoots into blade in the cup; falls to the ground; takes root; and becomes the a Sea-weeds generally propagate from roots. b Molina, i. p. 316, in notis. mother of others, having the same remarkable property. The aphis (insect) is also viviparous in summer, and oviparous in autumn. Some seeds are thrown by the force of the surf, which, in some places, rises even to the height of ten fathoms. Lifted so high in air, the winds separate them, as they descend, from the particles of water, with which they rose, and waft them to the internal parts of the island. Some plants in the Pacific islands were probably originally marine. Cast upon the shore, they have vegetated: these have produced seeds, which, being carried by winds or birds higher from the sea, have accommodated themselves to the soil, in which they were thus accidentally thrown; and during a series of propagations have gradually assumed characters not originally belonging to them. The nymphæa alba has, in this way, been the patriarch of many plants, now differing in shape and habit from itself. This vegetable, like many other aquatic plants, at the time of flowering, rises to the surface of the water in the morning it expands its blossoms, and towards evening closes them again. Many trees, such as the oak, beech, and hazel, are planted by squirrels and ravens; and the cinnamon of Ceylon and Malabar are propagated by the Pompadour pigeon; which drops the fruit, as it is carrying it to its young. The doves of Banda swallow seeds whole, and expel them whole; and in this manner propagate the nutmeg. The missel lives on the berries of the misseltoe, and propagates it from tree to tree. Some weeds are disseminated by the winds; as mosses, fungi, and mucor. The leather-cup has a seed so small, that it is almost imperceptible. This, and many seeds of similar minuteness, are conveyed in the leaves and trunks of trees. Some are fixed by the winds to the coats of animals; the feathers of birds; the sides of ships; and others to the backs of insects. Some seeds have species of feathers, which enable |