CHAPTER XIII.

GEOLOGICAL CHRONOLOGY--REMARKS ON THE SUCCESSION OF ORGANIC LIFE.

Summary of the History of Stratified Rocks--Striking Characteristics of certain Formations--Human Remains found only in superficial Deposits--Gradual Transition from the Organic Life of one Period to that of the next--Evidence in favor of this Opinion--Advance from Lower to Higher Types of Organic Life as we ascend from the Older to the more Recent Formations --Economic Value of Geological Chronology--Illustration--Search for Coal--the Practical Man at Fault--the Geologist comes to his aid, and saves him from useless Expense, 217