PRESERVATION 15 



Kensington. Even soft jelly-fishes have left their mark on 

 certain rocks ! At a place in Bavaria, called Solenhofen, there 

 is a remarkably fine-grained limestone containing a multitude of 

 wonderful impressions. This stone is well known to lithographers, 

 and is largely used in printing. On it the oldest known bird has 

 left its skeleton and faithful impressions of its feathers. 



The footprints of birds and reptiles are by no means uncommon. 

 Such records are most valuable, for a great deal may be learned 

 from even a footprint as to the nature of the animal that made it 

 (see p. 41). 



Since the greater number of animals described in this book are 

 reptiles, quadrupeds, and other inhabitants of the land, and only 

 a few had their home in the sea, we must endeavour to try and 

 understand how their remains may have been preserved. Our 

 object in writing this book is to interpret their story, and, as it 

 were, to bring them to life again. Each one must be made to tell 

 its own story, and that story will be far from complete if we 

 cannot form some idea of how it found its way into a watery 

 grave, and so was added to Nature's museum. For this purpose 

 we must briefly explain to the reader how the rocks we see 

 around us have been deposited ; for these rocks are the tombs in 

 which lost creations lie. 



Go into any ordinary quarry, where the men are at work, 

 getting out the stone in blocks to be used in building, or for use 

 on the roads, or for some other purpose, and you will be pretty 

 sure to note at the first glance that the rock is arranged as if it 

 had been built up in layers. Now, this is true of all rocks that 

 have been laid down by the agency of water as most of them 

 have been. True, there are exceptions, but every rule has its 

 exceptions. If you went into a granite quarry at Aberdeen, or a 

 basalt quarry near Edinburgh, you would not see these layers ; 



