It is (says Olbers) a remarkable but hitherto unregarded fact, that
while shells are found in secondary and tertiary formations, no Fossil
Meteoric Stones have as yet been discovered. May we conclude from this
circumstance, that previous to the present and last modification of the
earth’s surface no meteoric stones fell on it, though at the present
time it appears probable, from the researches of Schreibers, that 700
fall annually?[24]