1835.] DISTRIBUTION Of THE ORGANIC BEINGS. 289 



Albemarle Island, of the twenty-six aboriginal Galapageian plants, 

 tv enty-two are confined to this one island, that is, only four are at 

 present known to grow in the other islands of the archipelago ; and so 

 on, as shown in the above table, with the plants from Chatham and 

 Charles Islands. This fact will, perhaps, be rendered even more- 

 striking, by giving a few illustrations : thus, Scalesia, a remarkable 

 arborescent genus of the Composite, is confined to the archipelago ; it 

 has six species ; one from Chatham, one from Albemarle, one from 

 Charles Island, two from James Island, and the sixth from one of the 

 three latter islands, but it is not known from which ; not one of these 

 six species grows on any two islands. Again, Euphorbia, a mundane 

 or widely distributed genus, has here eight species, of which seven are 

 confined to the archipelago, and not one found on any two islands ; 

 Acalypha and Borreria, both mundane genera, have respectively six 

 and seven species, none of which have the same species on two islands, 

 with the exception of one Borreria, which does occur on two islands. 

 The species of the Composite are particularly local ; and Dr. Hooker 

 has furnished me with several other most striking illustrations of the 

 difference of the species on the different islands. He remarks that 

 this law of distribution holds good both with those genera confined to 

 the archipelago, and those distributed in other quarters of the world ; in 

 like manner we have seen that the different islands have their proper 

 species of the mundane genus of tortoise, and of the widely distributed 

 American genus of the mocking thrush, as well as of two of the Galapa- 

 geian sub-groups of finches, and almost certainly of the Galapageian 

 genus Amblyrhynchus. 



The distribution of the tenants of this archipelago would not be nearly 

 so wonderful, if, for instance, one island had a mocking-thrush, and a 

 second island some other quite distinct genus ; if one island had its 

 genus of lizard, and a second island another distinct genus, or none what- 

 ever ; or if the different islands were inhabited, not by representative 

 species of the same genera of plants, but by totally different genera, as 

 does to a certain extent hold good ; for, to give one instance, a large berry- 

 bearing tree at James Island had no representative species in Charles 

 Island. But it is the circumstance, that several of the islands possess 

 their own species of the tortoise, mocking-thrush, finches, and numerous 

 plants, these species having the same general habits, occupying 

 analogous situations, and obviously filling the same place in the natural 

 economy of this archipelago, that strikes me with wonder. It may 

 be suspected that some of these representative species, at least in the 

 case of the tortoise and of some of the birds, may hereafter prove 

 to be only well-marked races ; but this would be of equally great 

 interest to the philosophical naturalist. I have said that most of the 

 islands are in sight of each other ; I may specify that Charles Island is 

 fifty miles from the nearest part of Chatham Island, and thirty-three 

 miles from the nearest part of Albemarle Island. Chatham Island is 

 sixty miles from the nearest part of James Island, but there are two inter- 

 mediate islands between them which were not visited by me. James 

 Island is only ten miles from the part of Albemarle Island, but the 



