hese reefs in the course of
a year. I think most naturalists would be inclined to laugh at me for
making such an assumption, and would put the growth at certainly not
more than half that amount. But supposing it is so, what a very curious
notion of the antiquity of some of these great living pyramids comes out
by a very simple calculation. There is no doubt whatever that the sea
faces of some of them are fully a thousand feet high, and if you take
the reckoning of an inch a year, that will give you 12,000 years for the
age of that particular pyramid or cone of coral limestone; 12,000 long
years have these creatures been labouring in conditions which must have
been substantially the same as they are now, otherwise the polypes could
not have continued their work. But I believe I very much understate both
the height of some of these masses, and overstate the amount which these
animals can form in the course of a year; so that you might very safely
double the period as the time during which the Pacific Ocean, the
general state of the climate, and the sea, and the temperature has been
substantially what it is now; and yet that state of things which now
obtains in the Pacific Ocean is the yesterday of the history of the life
of the globe. Those pyramids of coral rock are built upon a foundation
which is itself formed by the deposits which the geologist has to deal
with. If we go back in time and search through the series of the rocks,
we find at every age of the world's history which has yet been examined,
accumulations of limestone, many of which have certainly been built
up in just the same way as those coral reefs which are now forming the
bottom of the Pacific Ocean. And even if we turn to the oldest periods
of geologic history, although the nature of the materials is changed,
although we cannot apply to them the same reasonings that we can to the
existing corals, yet still there are vast masses of limestone formed of
nothing else than the accumulations of the skeletons of similar animals,
and testifying that even in those remote periods of the world's history,
as now, the order of things implies that the earth had already endured
for a period of which our ordinary standards of chronology give us not
the slightest conception. In other words, the history of these coral
reefs, traced out honestly and carefully, and with the same sort of
reasoning that you would use in the ordinary affairs of life, testifies,
like every fact t