CHAPTER XVIII 



THE THEORIES OF ATOLL AND REEF FORMATION 



PUT FORWARD UNTIL THE PUBLICATION OF 



DARWIN'S THEORY OF SUBSIDENCE 



It is only to be expected that so strange a geographical 

 formation as a coral atoll should have given rise to abun- 

 dant speculation on the part of thinking people ; and when 

 the origin of these isolated rings of dry land in the midst of 

 great oceans came first to be considered much difference 

 of opinion prevailed. Even to-day it cannot be said that 

 there is complete unanimity. 



Atolls have always been mysterious, and I do not think 

 that I underrate the state of the present-day knowledge when 

 I say that the mystery even now is not entirely cleared away. 

 When, for the explanation of a fact in Nature, you may find 

 to hand many rival theories, whose several makers put them 

 forward as individually adequate, then it is certain that the 

 explanation of that fact is still to be made clear, either by 

 reconciling the contending theories or by establishing a new 

 one in the place of all. 



Concerning the origin of atolls, the warfare of rival 

 explanations cannot be said to have yet ceased ; and the 

 number of theories that have been brought forward from time 

 to time shows plainly that the halo of mystery, with which 

 the early navigator endowed the coral rings, has to this day 

 remained in the minds of many. Travellers' accounts of all 

 that they saw and heard, when far from their fellow-men, 

 have undergone a regular evolution, just as the travellers 

 themselves have done : and the evolution and progress of 

 modern scientific travel is easily followed in the literature left 

 behind by successive generations of pioneers. In the early 



212 



