What is the force by which these molecular changes have been effected?
SECTION III.
In what ways are geological changes produced by human agency?
Of what are the organic remains, in rocks, the record?
What rocks contain organic materials in large quantity?
What is the most abundant organic product?
Explain the mode of growth of corals.
Give instances of extensive coral reefs.
What is the total amount of surface covered by the coral reefs?
SECTION IV.