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Show 346 GEOGRAPHICAL DISTRIBUTION. [CHAP. XII. ground, and thus get transported ~ It occurred to me that land-shells, when hy bernating and having a membranous diaphragm over the mouth of the shell,.~njght b.e floated in chinks of drifted timber across moderately w1de arms of the sea. And I found that several species did in this state withstand uninjured an immersion in sea-water durinp; seven days : one of these shells was the Helix pomatia, and after it had again hybemated I put it in sea-water for twenty days, and it perfectly recovered. As this species has a thick calcareous operculum, I removed it, and when it had formed a new membranous one, I immersed it for fourteen days in sea-water, and it recovered and crawled away : but more experiments are wanted on this head. The most striking and important fact for us in regard to the inhabitants of islands, is their affinity to those of the nearest mainland, without being actually the same species. Numerous instances could be given of this fact. I will give only one, that of the Galapagos Archipelago, situated under the equator, bet,veen 500 and 600 miles from the shores of South America. Here almost every product of the land and water bears the unmistakeable stamp of the American continent. There are twenty-six land birds, and twenty-five of these are ranked by Mr. Gould has distinct species, supposed to have been created here; yet the close affinity of most of these birds to American species in every character, in their habits, gestures, and tones of voice, was manifest. So it is with the other animals, and with nearly all the plants, as shown by Dr. I-Iooker in his admirable memoir on the Flora of this archipelago. The naturalist, looking at the inhabitants of these volcanic islands in the Pacific, distant several hundred miles from the continent, yet feels that he is standing on American land. Why should this be so~ why should the species which are supposed to have been created in the Galapagos Archipelago, and nowhere else, bear so plain a stamp of affinity to those created in America~ There is nothing in the conditions of life, in the geologica] nature of the islands, in their height or climate or in the proportions in which the several classes are associated together, which resembles closely the conditions of the South CRAP. XII.] OCEANIC ISLANDS. Am . ~ erwan coast : in fact there is . ity i~ all these respects. On th~ 0~fuiderable dissimilar-considerable deg-ree of resembl . er hand, there is a of the soil, in chmate height a~e ~n the volcanic nature tween the Galapagos 'and Ca ~n de size of the is~ands, bebut what an entire and absol~t d'ffi Verde :Archipelagos: itants ! The inhabitants of th 0 I erence In their inhabrelated to those of Africa like thpe de Verde Islands are America. I believe this 'rand ose of the ~alapagos to explanation on the ordina~y vi fac; .c~n receive no sort of whereas on the view hei·e m ~wt ~ In ependcnt creation · h ain ained · t · b · ' t e Galapagos Islands would be lik 1 ' I IS ? VIous that whether by occasional means of t e Y to receive colonists, continuous land, from America. ra~port or by formerly Islands from Africa . and th t' an h the Cape de Verde liable to modification' ·-the ~i s~c col~nists. would be beti"_aying their origin~l birthp l~~~ple of Inhentance still Many ~nalogous facts coufd be i . . . . almost umversal rule that th ~ ve~ · mdeed It Is an islands are related to those of th en ernie pro~uctions of other near islands The e fe nearest continent, or of them can be expiained Thep Ions are few, and most of Land, though standing ~eareru: tl£ plan~s of Kerguelen are related, and that ver cl ~ rica t en to America, Hooker's account to thore fsA y, a~ we know from Dr. that this island h~s been ? menca: but on the view ~ith earth and stones on ~:~nly stoc~ed by seeds brought mg currents, this anomaly d ~rgs, drifted by the prevailits endemic plants is mu h Isappears. New Zealand in lia, the nearest mainlan~ thore tclosely related to Austrathis is what might hav' ban o any other region : and plainly related to South eA. een. expect~d ; but it is also next nearest continent . merica, which, although the . fact becomes an anomal Is so eno~mo~sly remote, that the pears on the view that t~th ~t th~ difficulty almost disap-and other southern 1 d ew ea and, South America !,rom a nearly interm:~ia~ew~he lohg ;go parti~lly stocked lrom the antarcti . I d oug Istant point, namely vegetation, before ~h~ can s, when they were clothed with The affinity, which th omhe~cebmlent of the Glacial period. ' oug lee e, I am assured by Dr. |