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Show 34:0 GEOGRAPHICAL DISTRIBUTION. [CHAP. XII. He who admits the doctrine of the creation of each separate species, will have to admit, that a sufficient number of the best adapted plants and animals have not been created on oceanic islands ; for man has unintentionally stocked them from various sources far more fully and per-fectly than has nature. Although in oceanic islands the number of kinds of inhabitants is scanty, the proportion of endemic species (i. e. those found nowhere else in the world) is often extremely large. If we compare, for instance, the number of the endemic land-shells in Madeira, or of the endemic birds in the Galapagos Archipelago, with the number found on any continent, and then compare the area of the islands with that of the continent, we shall see that this is true. This fact might have been expected on Iny theory for, as already explained, species occasionally arriving afte; long intervals in a new and isolated district, and having to compete with new associates, will be eminently liable to modification, and will often produce groups of modified descendants. But it by no means follows, that, because in an island nearly all the species of one class are peculiar, those of another class, or of another section of the same class, are p~culia~ ; and this d~:fference sem'?s to del?end. on t?e specieS' which do not become modified having Immigrated with facility and in a body, so that their mutual relations have not been much disturbed. Thus in the Galapagos Islands nearly every land-bird, but only two out of the eleven marine birds, are peculiar; and it is obvious that marine birds could arrive at these islands more easily than land-birds. Bermuda on the other hand, which lies at about the same distance from North America as the Galapagos Islands do from South America, and which has a very peculiar soil, does not possess one endemic land-bird; and we know from :Mr. J. M. Jones's admirable account of Bermuda, that very many North American birds, during their great annual migrations, visit either periodically or occasionally this island. Madeira does not possess one peculiar bird, and many European and African birds are almost every year blown there, as I am informed by Mr. E. V. Harcourt. So that these two • OH.AP. XII.) OCEANIC ISLANDS. . isiands of Bermuda and Ma . 841 bir~s, which for lonO' a . dmra have been stocked b their former homes, ~d ~~~ehave struggled together i~ ~~ ~ch·tlthher; and when settleJ1~oilie. mutually adapted In WI ave been ke t b mr new homes each filaces and ha.b its' and WPI. ll cyo ntsh e others to theii"' p'r oper able to modification. Madeir eque~tly_ have been little won~erful number of peculiar 1:~ again, IS inhabited by a species of sea-shell is confined ~-shells, whereas not one we dQ not know how sea-shel to Its s~lores: now, thou h see tha~ the}r eggs or larvre l!rhe dispersed, yet we c~n or floating timber or to th 1 p aps attached to seaweed t tdf: ranspor e ar mo' re easil e1the etofwad I' ng-bI' rds, might be or four hundred miles of Y an land-shells, across three of insects in Madeira appa~pe~ sea. The different orders Oceanic islands ai·e en :f present analogous facts I d sometimes d fi · · c asses, an their places a e Cient in certain ?ther inhabitants; in the G~l:P~!rently occupied by the m New Zealand giO'antjc . P1 5os ~slands reptiles, and ofmammals. In tfe lantWI~g ess birds, take the place ~ooker has shown thft th: o ~the ~alapagos islands, Dr. different orders are very d Jft. oportional numbers of the elsewhere. Such cases are IO' erent from what they are t~e physical conditions of th o~~er~ly accounted for by tiOn.seems to me not a littl ~ Isba~ s; but this explanagratwn, I believe, has beene ou t ul. ~acility of imminature of the conditions. at least as Important as the Many remarkable little f: . . ~pect to. th.e inhabitants of re~ts co.uld be given with re-m dert!llilislands not tenanted ote Islands. For instance, en e~IC plants have beautif y mammals, some of the relatwns are more strjk' th ully hooked seeds. yet few ~s for transportal b;~ie ;n ~he adaptation of hooked se:J clll!e presents no difficult o~n ::d f~r of quadrupeds. nnglit be transported t~ ·) VIew, for a hooked means,; and the plant th an . Is and by some other d but .still retaining its hoeonk bdecomding slightly modified deimm 1e spe C·i es, h avi.n O' as usele see s ' wo u ld l~O rm an en-' entary organ,-f~r in ess an appendage as an ru-under the soldered elytra ;;ance, ~s the shrivelled Jmgs many Insular beetles. Again, |