324 
APPENDIX II. 
appointed for exploded hypotheses. To this opinion I 
cannot declare myself a convert, for reasons which, in 
conclusion, I shall endeavour to indicate. 
First, however, I may remark that certain of Mr. 
Darwin’s critics occasionally appear to have perused his 
book with overmuch haste, and to have overlooked the 
fact that he admits such possibilities as local upheavals, 
the lateral growth of reefs, and modes of formation similar 
to those asserted for the Florida reefs ; 1 that in short, most 
of the causes on which stress has been laid by his critics 
have been already noticed by him, so that he differs from 
them, not in overlooking such causes, but in assigning 
to them a subordinate value. Moreover, it may not be 
unfair to call attention to the want of unanimity among 
his opponents : some advocating solution as a primary cause 
in the shaping of atolls, while others rely chiefly on the 
mode of growth of the polyps. Such a divergence obviously 
does not prove Mr. Darwin right, but it does indicate that 
as yet no other hypothesis has been able to secure a general 
acceptance, and that the problem still demands the exercise 
of cautious induction, which was his method of procedure, 
and does not justify the over-confident boldness of assertion 
which has characterised at least one critic of his work. 
The chief arguments which have been advanced against 
Mr. Darwin’s theory, as it appears to me, may be thus 
summarised : — 1. That such evidence as can be obtained 
in regions where extensive coral reefs exist is favourable 
to upheaval rather than to subsidence. 2. That lateral 
growth is a most important factor in the formation of a reef, 
the polyps, as they advance, being supported on a founda- 
tion composed partly of the broken fragments of the reef, 
partly of other marine organisms, and that by means of the 
latter deeply submerged banks are sometimes augmented 
vertically until they are brought within the zone of reef-coral 
1 See pp. 22, 23, 79, 120, 121, 174, etc. 
