208 THE GALAPAGOS. [CH. IV 



originally populated, and during that time the descendants 

 of the original migrants have had time to pursue an 

 independent line of development. That Kerguelen is an 

 island of some antiquity is shown by the submerged bank 

 which surrounds it, which would have demanded time for 

 its submergence, and by the occurrence of stratified, 

 though originally volcanically produced, rocks. We now 

 come to the remarkable case of the Galapagos. Reptiles 

 are often not totally wanting in islands of purely oceanic 

 type ; there seems to be some method, at present mys- 

 terious, in which reptiles have the advantage over 

 mammals in traversing the sea. So that the actual 

 presence of lizards and snakes, though they are rather 

 numerous, is not an absolute bar to regarding the 

 Galapagos as of purely oceanic origin. The great tortoises 

 seem to be a huge difficulty ; there is no way of slipping 

 out of the problem by bringing in the help of settlers ; 

 besides, in another island, Aldabra, there are also huge 

 tortoises. This island belongs to the Comoro group lying 

 at some distance from Madagascar but connected with it 

 by a shallow of about 1,000 fathoms in depth. There is 

 much the same relation between Aldabra and Madagascar 

 that there is between the Galapagos and the South 

 American continent. But in neither case could these 

 huge tortoises, sometimes weighing 700 pounds, have 

 swum across a wide and deep ocean. And the fact that 

 the first visitors to the Galapagos mention them shows 

 that they have not been introduced by man. 



Dr Baur thinks that these tortoises are of themselves 

 almost sufficient to prove the former connection of the 



