FOSSILS 219 



cry, ''the wind blew and rippled the water in the httle 

 pool on the beach long, long ago." Or if we see the 

 pitted marks upon the sandstone, we think, ''The 

 falling drops made these in the days when there 

 were no little children to run under cover to get away 

 from those heavy raindrops." 



Do you understand, then, why the rocks form a 

 wonderful book of knowledge? They write for us the 

 history of the world itself. Men write for us the 

 history of what people have done upon the earth ; but 

 the rocks tell us more than about themselves, they 

 tell us what plants and creatures lived upon the 

 world before we came here, and before the animals 

 came that live here with us now. 



Would you like to know how the rocks tell these 

 things? Then think of the sea beach with all the 

 shells buried under the sand. Think of the sand be- 

 ing pressed into sandstone, and then being forced up 

 to the surface of the earth ! 



Then when men cut into the sandstone, and take 

 out the blocks, what do they find there? The shapes 

 of the perfect shells ! The shapes of things that really 

 lived on this world in those long ago days when the 

 world looked so different from what it does now. Is 

 not that like reading a book, — a book, moreover, that 

 is all filled with pictures? 



Many different kinds of shells are found pictured 

 in these rocks, and not one of them is shaped just like 

 any that we have now. There were coral insects in 

 those early seas building their branching reefs. Later 

 there were starfishes and sea urchins, but all were 

 different from those that are now in existence. 



