146 LEISURE-TIME STUDIES. 



at its greatest width, the latter being the measurements of 

 one of the Maldive atolls. As in the previous case, this 

 theory demands the recognition of the existence of numerous 

 volcanic chains all existing within a limited depth of the 

 surface ; and, in view of the utter want of evidence to show 

 that any such immense volcanic area ever existed, this sup- 

 position must be unhesitatingly rejected. One further idea 

 emanating from Chamisso may be lastly noted. This author 

 held that, as the reef-building corals love the surf, the outer- 

 most parts of the reef will tend first to reach the surface 

 and so assume a circular form* But this idea assumes that 

 the foundations of the reef in such a case consist of a flat 

 bank, and the existence of such foundations is, as we have 

 already noted, inconsistent with fact. The origin of barrier 

 reefs did not receive from the naturalists and geologists of 

 the past the same amount of attention as the question of the 

 nature and origin of atolls, a result due to the apparently 

 more recondite character of the latter problem. The great 

 Australian barrier reef was alleged to be founded " on the 

 edge of a submarine precipice parallel to the shore." This 

 idea may be dismissed with the remark that no evidence is 

 afforded that any such precipice or plateau exists. 



It may be affirmed that until the year 1842 no theory of 

 the origin of coral-reefs which stood the test of scientific 

 cross-examination was promulgated. In that year Mr. Dar- 

 win gave to the world his views on this subject, and enun- 

 ciated a theory which has firmly stood its ground against 

 the most severe examination and criticism, and which at the 

 present time remains as the only feasible theory of the origin 

 of coral-reefs. If it be taken as a test of the truth of a 

 hypothesis that it intelligently explains all the facts of a case 

 and is found to be inconsistent with none, then Mr. Darwin's 

 ideas may be regarded as constituting a theory of the most 

 perfect kind. And it may be fearlessly affirmed that, had 

 Mr. Darwin accomplished no further investigation than his 

 researches on coral-reefs, he would have been entitled to 

 the admiration and gratitude of all who regard the advance- 



