298 MISCELLANEA. [ch. xv. 



" After the appearance of Semper's work, Dr. J. J. Rein 

 published an account of the Bermudas, in which he opposed 

 the interpretation of the structure of the islands given by 

 Nelson and other authors, and maintained that the facts ob- 

 served in them are opposed to the views of Darwin. Al- 

 though so far as I am aware, Darwin had no opportunity of 

 studying and considering these particular objections, it may 

 be mentioned that two American geologists have since care- 

 fully re-examined the district Professor W. N. Rice in 

 1884 and Professor A. Heilprin in 1889 and they have in- 

 dependently arrived at the conclusion that Dr. Rein's objec- 

 tions cannot be maintained. 



" The most serious objection to Darwin's coral-reef the- 

 ory, however, was that which developed itself after the re- 

 turn of H. M. S. Challenger from her famous voyage. Mr. 

 John Murray, one of the staff of naturalists on board that 

 vessel, propounded a new theory of coral-reefs, and main- 

 tained that the view that they were formed by subsidence 

 was one that was no longer tenable ; these objections have 

 been supported by Professor Alexander Agassiz in the 

 United States, and by Dr. A. Geikie, and Dr. H. B. Guppy 

 in this country. 



" Although Mr. Darwin did not live to bring out a third 

 edition of his Coral Reefs, 1 know from several conversa- 

 tions with him that he had given the most patient and 

 thoughtful consideration to Mr. Murray's paper on the sub- 

 ject. He admitted to me that had he known, when he 

 wrote his work, of the abundant deposition of the remains 

 of calcareous organisms on the sea floor, he might have re- 

 garded this cause as sufficient in a few cases to raise the 

 summit of submerged volcanoes or other mountains to a level 

 at which reef-forming corals can commence to flourish. 

 But he did not think that the admission that under certain 

 favourable conditions, atolls might be thus formed without 

 subsidence, necessitated an abandonment of his theory in 

 the case of the innumerable examples of the kind which 

 stud the Indian and Pacific Oceans. 



"A letter written by Darwin to Professor Alexander 

 Agassiz in May 1881, shows exactly the attitude which care- 

 ful consideration of the subject led him to maintain towards 

 the theory propounded by Mr. Murray : 



" i You will have seen,' he writes, ' Mr. Murray's views 

 on the formation of atolls and barrier reefs. Before pub- 

 lishing my book, I thought long over the same view, but 



