184 Davis — Dana's Confirmation of 



book on this subject, " On Coral Keefs and Islands,"* and 

 in the several editions of his larger book, " Corals and Coral 

 Islands."f 



It is singular how seldom the value of Dana's significant 

 evidence has until recent years been appreciated by other 

 students of coral reefs. It is inconspicuously referred to in 

 the appendix to the third edition of Darwin's " Coral Reefs " 

 (London, 1889), prepared by Bonney, who says in this connec- 

 tion that fiord-like indentations in the rocky coasts of islands 

 are " generally admitted to be one of the strongest evidences 

 of subsidence all the world over" (310-311), but the editor 

 does not draw special attention to this evidence as affording an 

 independent and therefore highly valuable confirmation of 

 Darwin's theory. Dana's statement is noted by Kramer, $ who 

 gives it local application in explaining certain bays of the 

 Samoan islands, but he fails to recognize its general value in 

 relation to the subsidence theory of coral reefs. It is quoted 

 by Gardiner,§ but without recognition of its importance, for he 

 says : " Such evidence when applied to volcanic islands is, I 

 submit, of very doubtful value." Murray does not mention 

 Dana's evidence ; Agassiz rejects it, for he writes : " There 

 are ... no indications that either the Marquesas or Mehetia has 

 been subjected to the effects of subsidence, as Dana assumes."] 

 Dana's statement in this connection was : " The Marquesas are 

 remarkable for their abrupt shores, often inaccessible cliffs, 

 and deep bays. The absence of gentle slopes along the shores, 

 their angular features, abrupt soundings close alongside of the 

 island, and deep indentations, all bear evidence of subsidence 

 to some extent ; for their features are very similar to those 

 which Kaui or Tahiti would present, if buried half its height 

 in the sea, leaving only the sharper ridges and peaks out of 

 water."^[ Evidently, then, the importance of Dana's contribu- 

 tion to Darwin's theory has been slow in gaining general 

 recognition. This is probably because an understanding of the 

 reasonable evolution of coastal forms has not yet gained general 

 possession of the scientific mind ; or perhaps because some 

 students of the coral reef problem still adhere to the obsolete 

 explanation of bays by marine erosion, an explanation which 

 Dana explicitly excluded ; can the delay in application of 

 Dana's principle to the coral reef problem be because there is 

 as yet no sufficiently general understanding of the principle 



* New York, 1853, 118-119. \ New York, 1872, 319-320, and 1890, 273-274. 



JBau der Korallenriffe, Leipzig, 1897, 24. 



§Proo. Camb. Phil. Soc, ix, 1898, 490. 



| "Coral Eeefs of the Tropical Pacific," Mem. Mus. Comp. Zool., 1903, 

 xxviii, 5. 



IT "Coral Eeefs and Islands," New York, 1853, 122; "Corals and Coral 

 Islands," New York, 1872, 325. 



