1904-1905-] Recent Views regarding Coral Reefs. 179 



the uplift in some parts may be continuous — i.e., without any- 

 stationary pauses between. This appears to have been the 

 case in the south of England, where the evidence of uplift is 

 quite clear, but where there are no rocky shelves carved on 

 the shore-line, such as happen when the sea works for a long 

 time on a coast-line not undergoing any elevation. Some 

 coral islands which have been carried above sea-level by these 

 terrestrial movements fail to show any trace of the terraces in 

 question. But the majority show long lines of cliff, with 

 their bases one above another, and with lines of sea caverns 

 now situated far above the plane at which any such caverns 

 could be wrought by the sea now. The importance of these 

 terrestrial movements may be judged of from the fact that 

 reefs of coral in no respect different from those now 

 forming in the seas adjacent occur hundreds of feet above 

 the level at which they were found, and in some few cases 

 even more than a thousand feet up. The frequent associ- 

 ation of these upraised banks of coral rising tier above tier 

 to considerable elevations above the sea is a fact of con- 

 siderable importance in connection with the modern views 

 regarding the history of coral reefs in general. It is be- 

 coming quite clear to most persons who have thought well 

 over the facts, that coral reefs, as a rule, are most common 

 where the sea-bottom is undergoing elevation. There is no 

 reason why corals should not grow in a stationary area, or 

 even in one that is subsidiary, provided that the other con- 

 ditions are suitable. But elevation, as a rule, seems to 

 prevail. 



There are many areas of upraised coral reefs in which the 

 base of the reef is exposed, and in which, therefore, the nature 

 of the foundation upon which the reef started can be exam- 

 ined. In several cases, as might be expected, the base con- 

 sists of volcanic material, and it is evident that the corals 

 perched upon the summit of a submarine volcano, which, with 

 its crown of corals, has afterwards been upheaved into land. 

 This coincidence of upraised coral reefs with volcanoes is not 

 accidental, for there is a growing belief that volcanic action is 

 chiefly caused by the heat generated by movements of up- 

 heaval of the Earth's crust ; and further, access of sea-water 



