SUBSIDENCE AND UPHEAVAL. 255 



described make the theory of a recent subsidence untenable as 

 regards the southern portion of the group, without our being 

 obliged to deny the possibility of such action, for the whole 

 group. If, for instance, it is assumed that the subsidence has 

 not taken place equally, but that by a sort of tilt the northern 

 portion has subsided most, the middle but very little, and the 

 south not at all, all the observed phenomena might be accounted 

 for, or at least apparently explained. Nay, more, the pre- 

 sence of true fringing reefs to the extreme south of Pelelew, and 

 the total absence of all visible reefs round Ngaur, would, from the 

 point of view of the Darwinian theory, indicate a past process of 

 elevation of the region south of the axis, if it were assumed that 

 this point of equilibrium and perfect rest had been somewhere 

 near the northern point of Pelelew. 



Now I shall lay no great stress on the internal improba- 

 bility of the hypothesis that such an unequal movement should 

 actually have occurred in so small an area, which, besides, rises 

 from the depths of the ocean perfectly isolated from other 

 groups of islands. Indeed, the difficulties here raised would by 

 no means be removed in this way; they would rather be 

 essentially enhanced, from the fact that south of Ngaur a 

 submarine reef is found very near to that island, and its 

 being divided from it can be explained only by supposing that 

 some other forces have been at work besides subsidence only. 

 Thus even if it were admitted, in spite of the facts which are 

 directly opposed to it, that the impossibility of such a subsidence 

 is not conclusively proved by them, we should still be com- 

 pelled to acknowledge that the influence of the constant cur- 

 rents must be, in all cases, an essential factor in the history of 

 the origin and formation of these islands. For, to insist once 

 more very positively on this point, during subsidence the coast- 

 line of the sinking island would necessarily be preserved, as 

 Darwin even will admit ; but this, as is proved by my data, has 

 not been the case, and hence the subsidence theory, by itself, 

 ceases to be applicable. This, naturally, narrov/s its whole 

 general value; for if it is impossible in a special case like the 

 present to explain the circumstances by the only force which 

 that theory admits to be efficient and determining, and if, in- 



