172 bulletin: museum of compakattve zoology. 



explanation of their formation than that suggested by Darwin, and thus 

 call upon factors which he had relegated to a subordinate value. The 

 want of unanimity among the opponents of the Darwinian theory of the 

 formation of coral reefs has, it seems to me, nothing to do with the ques- 

 tion whether Darwin is right or not. It merely shows that there are 

 many points of difference which are more or less apparent in the various 

 districts examined by recent writers on coral reefs, and that perhaps the 

 problem of their formation is not quite so simple as the upholders of the 

 subsidence theory would have us believe. 



The disadvantages of a discussion of the theory of the formation of 

 coral reefs by one who has not faced the problem in the field are appar- 

 ent in the essay of Dr. R. Langenbe'ck. It undoubtedly is a most useful 

 summary, and, while the writer has endeavored to retain an impartial 

 attitude, his views naturally do not carry much weight, based as they 

 are only upon cartographic knowledge, and consisting in great part of 

 special pleading in favor of the theory of subsidence. His essay does 

 not seem to me to have the importance assigned to it by Huxley in his 

 discussion of the article on "A Conspiracy of Silence," 1 by the Duke of 

 Argyll. This and similar essays can give us only interesting speculations, 

 of little value except when tested by observations. 



Dr. Langenbeck has been unfortunate in the exposition which he gives 

 of the Florida and West India reefs. His description of the reefs of Cuba 

 and of the Bahamas differs greatly from that given by the writers from 

 whom he has taken his data. But he is the first writer on the theory of 

 reefs who, while of the opinion that the theory of Darwin is the only one 

 which can explain the formation of atolls in the extensive tracts of the 

 Pacific where atolls are so numerous, yet acknowledges that there are 

 extensive districts in which the formation of reefs has not been influ- 

 enced by subsidence. This was the principal point at issue between the 

 earlier opponents of the theory of subsidence. Subsequent investiga- 

 tions in the Pacific and elsewhere have shown most clearly that the reef 



1 I am unable to understand the statement of Professor Heilprin (The Bermudas, 

 p. 21) regarding the authority of " A Conspiracy of Silence." It is most extraordi- 

 nary if, as is stated by Heilprin, the " younger school of geologists " have pinned their 

 faith to the statements of its author and have chosen for their leader one who has 

 never made any original observations on the subject of coral reefs. The great ma- 

 jority of recent observers of coral reefs have stated that the generally accepted 

 theory of their formation was not applicable to the particular district they exam- 

 ined. Each has endeavored to give an explanation of the facts, and they have 

 not " pinned their faith to any standard bearer," or to any theory, or to any leader, 

 or to any creed. 



