150 FORMATION OF CORAL REEFS. 
that prepared the earth for the coming of man, 
and the animals and plants that accompany him 
on earth, baffles our finite attempts to estimate 
its duration, have we any mearts of determining 
even approximately the length of the period to 
which we ourselves belong? If so, it may fur- 
nisb us with some data for the further solution 
of these wonderful mysteries of time, and it is 
besides of especial importance with reference to 
the question of permanence of Species. 
Those who maintain the mutability of Species, 
and account for all the variety of life on earth 
by the gradual changes wrought by time and 
circumstances, do not accept historical evidence 
as affecting the question at all. The relics of 
those oldest nations, all whose history is pre- 
served in monumental records, do not indicate 
the slightest variation of organic types from the 
earliest epoch to this day. The animals pre- 
served within their tombs or carved upon the 
walls of their monuments by the ancient Egyp- 
tians were the same as those that have their 
home in the valley of the Nile to-day; the 
negro, whose peculiar features are unmistaka- 
ble even in their rude artistic attempts to rep- 
resent them, was the same woolly-haired, thick- 
lipped, flat-nosed, dark-skinned being in the 
days of the Rameses that he is now. The 
Apis, the Ibis, the Crocodiles, the sacred Beetles, 
