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THE ORIGIN OF CORAL REEFS. 69 
REMARKS ON THE FOREGOING PAPER. 
By Mr. G. C. Bourne, M.A., F.LS. 
Dr. Guppy may fairly claim to be one of the greatest authorities 
on the subject of coral reefs, and I am somewhat shy of venturing 
to criticise his paper. 
His account of Pacific myths as bearing on the origin of atolls is 
most interesting, but personally I am not inclined to attach much 
value to them as giving evidence of the upheaval of these islands. 
The Malays of N. Celebes, for instance, have wonderful legends 
relating to the formation of nearly every hill and island in or 
adjoining to their country, and very few of them can give any 
insight into the formation of those hills and islands. It must not 
be forgotten that an island would appear to a party of savages in a 
sense to rise out of the waters as they approached it, and each 
newly-discovered island would thus be readily described as rising 
out of the sea; the legendary stories would subsequently group 
themselves round the names of the first colonisers of the newly- 
discovered. island. 
I agree cordially with Dr. Guppy in thinking that the vast 
majority of atolls and barrier-reefs have remained in their present 
condition for upwards of three centuries. As to the extremely slow 
rate of coral growth, the evidence, which I have carefully considered, 
is very conflicting. All that can be certainly said is, that some 
species of coral grow far more rapidly than others, and that identical 
species vary very much in their rate of growth according as the 
conditions to which they are exposed are favourable or the reverse. 
Dr. Guppy, apparently quoting Mr. Darwin, says that the coral 
knolls of Digo Garcia have remained stationary for upwards of 
eighty years. This is hardly the case. I have most carefully 
compared the chart made by H.M.S. Rambler in 1885 with that 
made by Captain Moresby in 1837, and find that the knolls marked 
in the two charts rarely correspond with one another. Where they 
do correspond they are sometimes marked with a less depth in the 
later survey, sometimes with a greater. Some allowance must be 
made for errors of observation, but the chart of the Rambler shows 
conclusively that the reef westward of middle islet at the entrance 
of the lagoon has increased very largely since the original survey in 
1837, as also has the reef and the number of coral patches eastern- 
