MAROONED. 



139' 



and in the^e secure retreats to carry on their ancient race. 

 We seem, in our present modern days, to see something of 

 a similar occurrence, in the case of the elevated Nicaraguan 

 Lake, in which tarpon still exist, completely landlocked 

 and cut off from the sea. 



But the main result of all our peregrinations, to which 

 we must return, would be, that at last we should have 

 got some true conception of what Swan Island really 

 was ; that we were marooned upon the isolated coral- 

 crowned summit of a submarine mountain ; or to put it in 

 more scientific language, there had taken place in this 

 neighbourhood, in past geological ages, a gentle orogenic 

 movement of the earth's crust, which had gradually 

 elevated this submarine mountain summit to a plane 

 above the " limiting line of sedimentation," which 

 elevation had permitted the growth of reef -building 

 corals upon it, and so had, in the end, led to the 



formation of a coral island. 



* * * * 



But even so, we have not accounted for the marine 

 deposits which lie beneath the coral capping of our island. 

 In as few words as possible, we have endeavoured to 

 explain how this vastly contorted Honduran sea-bottom 

 has been affected by mighty subterranean forces, acting 

 on an unstable and plastic crust, until there is hardly any 

 sea-bottom like it in the world. We have seen how the 

 foundations of Swan Island had been gradually uplifted^ 

 until they attained to ^uch a height, that the surface 

 currents sweeping over them prevented the deposition 

 of sediment upon them, and so made it possible for reef- 

 building corals to grow and multiply. But, prior to this,, 

 something else had been taking place. 



This something else took the form of a constant rain 

 of the dead remains of millions of minute creatures (most 

 of them microscopic) which once lived upon or near the 

 surface of the sea, and which, when they had passed^ 

 through their little life-span, fell in a never ceasing shower,, 

 upon the slopes of our submarine mountain slopes. Here,. 



