258 GEOLOGY OF OHIO 



come at last for it to strike root. It has been living and growing ever 

 since. 



A young Swiss naturalist, Leo Lesquereux, was perhaps the first to 

 expand the suggestion into a theory of definite shape and proportions. 

 Called by the government of his own canton to report upon its peat beds 

 as a source of fuel, he took up the study of the bog and made himself 

 thoroughly master of its botany, its physics, its chemistry, its geology- 

 He extended his observations and studies, still under government patron, 

 age, to the peat bogs of northern Europe until he knew better than any 

 one had known be ore, the laws of their formation and growth. From 

 peat bogs he came to the study of coal. His field now lay on this side 

 of the Atlantic. He saw, or thought he saw, that the laws of the peat 

 bog could be applied to the coal seam; that the key, the only key, to the 

 history of the latter was to be found in the knowledge that he had 

 already acquired among the beds of fuel that are growing now but whose 

 roots go back into past millenniums. 



In its development, this theory appears to be almost an American 

 theory. It has found far wider acceptance here than elsewhere, and the 

 best statements of it all come from this side of the Atlantic. 



It was expounded very ably in the main by Henry D. Rogers in 

 the reports of the First Pennsjdvania Geological Survey, but his state- 

 ment was marred by the introduction of some dynamic features that are 

 quite foreign to our present thought and in which he has no followers. 



Dr. Newberry made one of the most compact and symmetrical 

 statements of it that has yet appeared, and he came to the subject with 

 large and fresh and independent knowledge from every part of the field. 

 Prof. E. B. Andrews repeatedly presented the theory in excellent shape, 

 basing his statements in the main on his own observations. 



But it still remains true that in view of the central and far-reaching 

 claims of the theory, no thoroughly worthy or adequate presentation of 

 it nas ever yet been made. We can go further and say that no near 

 approach has yet been made to such a presentation. All the statements 

 that we have are limited to a few pages each, designed for popular use 

 and falling far below the demands of scientific completeness and exact- 

 ness. 



While, therefore, there are considerable differences of view as to the 

 modes in which vegetation was accumulated in the Carboniferous swamps, 

 these differences concern points of minor value. All of the leading 

 theories have a great deal in common. 



As to the kinds of vegetation that make the chief contributions to 

 the formation of coal, a few words must suffice. 



The vegetable kingdom is divided into two principal sub-divisions, 

 viz., the Phanerogamia, or flowering plants, and the Cryptogamia, or flower- 

 less plants. These divisions are further sub-divided as follows : 



