1835.] DISTRIBUTION OF PLANTS. 391 



confined to this one island ; and in Albemarle Island, of the 

 twenty-six aboriginal Galapageian plants, twenty-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 

 CompositcB, 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 CompositcB 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 difi'erent 

 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 Galapageian 

 sub-groups of finches, and almost certainly of the Gala- 

 pageian genus A mblyrhynchus. 



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 whatever ; — 

 or if the different islands were inhabited, not by repre- 

 sentative 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 



