President's Address. 27 



probable that these comparatively few deep lagoons may 

 owe their depth partly to subsidence. But if this be the 

 case, it would lend, I am afraid, but slender support to a 

 theory of wide oceanic depression. That there must be some 

 areas of subsidence over the coral regions is almost certain, 

 and the few scattered deep lagoons may possibly indicate 

 some of these areas. 



Having thus fully examined the arguments on both sides 

 of this interesting and important question, I feel myself 

 reluctantly compelled to admit that Darwin's theory can no 

 longer be accepted as a complete solution of the problem of 

 coral-reefs. No one could be more impressed than myself 

 with the simplicity of this theory, the brilliancy of its gene- 

 ralisation, its remarkable fitness in geological theory, and the 

 grandeur of the conceptions of geographical revolution to 

 which it leads. I am fully alive to the serious changes 

 which its abandonment will make in some departments of 

 geological speculation. But in the face of the evidence which 

 has now been accumulated, I can no longer regard the ac- 

 cepted theory as generally applicable. That it may possibly 

 be true in some instances may readily be granted. There 

 may be areas of subsidence, as there certainly are areas of 

 elevation, over the vast regions where coral-reefs occur. It 

 may be conceded that subsidence may sometimes have pro- 

 vided the platform whereon coral-reefs have sprung up, and 

 may have contributed to heighten some reefs and to deepen 

 some lagoons and lagoon-channels. But I do not believe 

 that we are now justified in assuming subsidence to have 

 taken place, from the mere existence of atolls and barrier-reefs. 

 Its occurrence at any locality must be proved by evidence of 

 special local movement. It may have gone on at many 

 localities where atolls and barrier-reefs are found; but the 

 existence of such reefs is no more necessarily dependent upon 

 subsidence than upon elevation. These subterranean move- 

 ments must be looked upon as mere accidents in a general 

 process of coral-growth, which is wholly independent of them. 



I may, in conclusion, refer to one or two difticulties which 

 have long been felt to be serious drawbacks to the theory of 

 subsidence, but which disappear when the newer views of 



