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Show 252 ISLAND LIFE. [PART. 11. There can be little doubt that the truly indigenous flora of the islands is far more scanty than the number of plan~s recorded would imply, because a large but unknown pr~portwn of the species are certainly importations, voluntary or mvoluntary, b.y man. As, however, the general character of the whole flora IS that of the south-western peninsula of Europe, and as mo~t ~f the introduced plants have come from the same country, It IS almost impossible now to separate them, and Mr. Watson .has not attempted to do so. The whole flora contains representatives of eiahty natural orders and 250 genera; and even if we suppose that 5 one-half the species only are truly indigenous, there will still remain a wonderfully rich and varied flora to have been carried, by the various natural means above indicated, over 9.00 miles of ocean, more especially as the large proportion of speCies identical with those of Europe shows that their introduction has been comparatively recent, and that it is, probably (as in the case of the birds) still going on. We may therefore feel sure that we have here by no means reached the limit of distance to which plants can be conveyed by natural means across the ocean; and this conclusion will be of great value to us in investigating other cases where the evidence at our command is less complete, and the indications of origin more obscure or conflicting. Of the forty species which are considered to be peculiar to the islands, all are allied to European plants except six, whose nearest affinities are in the Canaries or Madeira. Two of the Compositre are considered to be distinct genera, but in this order generic divisions rest on slight technical distinctions; and the Oampanula vidalii is very distinct from any other known species. With these exceptions, most of the peculiar Azorean species are closely allied to European plants, and are in several cases little more than varieties of them. While therefore we may believe that the larger part of the existing flora reached the islands since the glacial epoch, a portion of it may be more ancient, as there is no doubt that a majority of the species could withstand some lowering of temperature ; while in such a warm latitude and surrounded with sea, there would always be many sunny and sheltered spots in which even tender plants might flourish. CHAP. Xll.] BERMUDA. 25~ Irnportant deduction from the peculia1·ities of the Azorean Fauna and FloTa.-There is one conclusion to be drawn from the almost wholly European character of the Azorean fauna and flora which deserves special attention, namely, that the peopling of remote islands is not due so much to ordinary or normal, as to extraordinary and exceptional causes. These islands lie in the course of the south-westerly return trades and also of the Gulf Stream, and we should therefore naturally expect that American birds, insects, and plants would preponderate if they were conveyed by the regular winds and currents, which are both such as to prevent European species from reaching them. But the violent storms to which the Azores are liable blow from all points of the compass; and it is evidently to these, combined with the greater proximity and more favourable situation of the coasts of Europe and North Africa, that the presence of a fauna and flora so decidedly European is to be traced. The other North Atlantic Islands-Madeira, the Canaries, and the Cape de Verdes-present analogous phenomena to those of the Azores, but with some peculiarities dependent on their more southern position, their richer vegetation, and perhaps their greater antiquity. These have been sufficiently discussed in my Geographical Distribution of Animals (Vol. I. pp. 208- 215); and as we are now dealing with what may be termed typical examples of oceanic islands, for the purpose of illustrating the laws, and solving the problems presented by the dispersal of animals, we will pass on to other cases which have been less fully discussed in that work. BERMUDA. The Bermudas are a small group of low islands formed of coral, and blown coral-sand consolidated into rock. They are situated in 32° N. Lat., about 700 miles from North Carolina, and somewhat farther from the Bahama Islands, and are thus rather more favourably placed for receiving immigrants from America and its islands than the Azores are with respect to Europe. There are about 100 islands and islets in all, but their total area |