Page:The Natural History of Ireland vol1.djvu/14

 thence. There are, however, instances of islands situated sufficiently near large continents to admit of the flight of birds from the latter, and yet deriving comparatively few, or none of their species from them. The most remarkable example is presented by the Galapagos archipelago, situated under the equatorial line, and which, though only 500 to 600 miles westward of the coast of South America, does not contain a land bird from the continent. Even some of the islands of the group have their peculiar species. Full information on this most interesting subject will be found in Mr. Darwin's excellent journal, kept during the Surveying Voyages of H.M.S. Adventure and Beagle, vol. iii. p. 461 and 473–478. Madagascar, the nearest part of which is only about 250 miles distant from the coast of Africa and extending about 1,000 miles in a parallel direction, offers another striking instance of an island not deriving its fauna from the neighbouring continent. Of 113 known species of birds of Madagascar, 68 are peculiar to it. The fullest information on the subject of the ornithology of that island will be found in a comprehensive essay by Dr. G. Hartlaub of Bremen, published in the Annals of Natural History for Dec., 1848, p. 383–396. For a knowledge of it, and its translation from a German journal, the English reader is indebted to Mr. H. E. Strickland.

It is interesting to observe how birds are affected by the opera-