The Origin of Coal 



which followed, for the coal which we find so useful 

 to-day is composed of the buried trunks, branches, 

 leaves, and seeds of the plants which grew during this 

 bygone age. The pressure of the overlying deposits 

 of mud and sand hardened the vegetable remains into 

 a solid mass, which, altered by chemical changes, was 

 finally transformed into coal. 



The subsequent changes which again altered the 

 earth's crust and finally moulded it into its present 

 form produced conditions under which these ancient 

 plants found it difficult to maintain their position in 

 the plant world. Some died out completely, while 

 others, as we have seen, lingered on, though in a very 

 degenerate form. Could we have lived under the con- 

 ditions which prevailed at that remote period, and have 

 seen the fern alliance in all its glory, and then have 

 slept, Rip Van Winkle-like, through the vast inter- 

 vening cycle of years, how great would be our astonish- 

 ment on awakening to behold how the former things 

 had passed away ! How difficult it would be to 

 persuade us that the degenerate ferns, clubmosses, and 

 horsetails, found in Britain to-day, are the descendants 

 of the luxuriant vegetation of long ago ! 



Yet, strange as it may appear, botanists are able to 

 prove this is really the case. 



We read of how fossil bones and shells have been 



found embedded in rocks, and we have no hesitation in 



believing that they are the remains of animals that lived 



ages ago. But plants are composed of a more perish- 



5 



