INTRODUCTION. V 



the earth's history the rocks of any given district belong, before 

 undertaking mining enterprises of any kind, will be readily 

 understood, and the intelligent general reader will at once 

 comprehend why it is that geologists give so much attention to 

 fossils. In short, the first and most important step in the 

 prosecution of a geological survey, is a careful and thorough 

 study and investigation of the organic remains found in every 

 seam and stratum of the rocks of the district to be explored ; 

 for without a knowledge of these, all conclusions in regard to 

 the geological structure of the country, or of the age and position 

 in the geological column of its rocks, must necessarily be vague 

 and unreliable. Indeed, without the aid of Palaeontology, 

 Geology would scarcely be entitled to rank as a science at all. 

 But aside from all mere utilitarian considerations, there is 

 much in the history of these mute relics of by-gone ages — 

 extending, as it does, deep into the mysterious past, and reveal- 

 ing, as it were, glimpses of the successive steps in the great 

 work of creation itself — that must ever render them objects of 

 the most profound interest to all reflecting minds. When it is 

 remembered, too, that the rocks of our State are unusually rich 

 in these interesting remains (to a great extent new to science), 

 we can scarcely be mistaken in supposing that the citizens of 

 the great State of Illinois will feel a commendable pride in 

 contributing their share to the general stock of knowledge, in 

 a department of science now claiming so much attention from 

 enlightened minds throughout the civilized world. Nor can 

 we believe the people of Illinois desire that the students of our 

 schools and colleges, and others, justly ambitious to keep pace 

 with the great minds of other lands, in every department of 

 learning, should be longer dependent upon reports published 

 by our neighboring States for a knowledge of these wonderful 

 works of the Creator, so profusely scattered at our feet, even if 

 it were possible to find the desired information there. Hence 

 we think any extended statement of the motives that have 



