j62 the chain of life. 



above could not often occur ; and it is therefore not wonderful 

 that only in one place and one bed has evidence of it been 

 found, and that even in this some of the trees have been filled 

 up at once by sand and clay, or so crushed by falling in or 

 lateral pressure, that they could receive no animal remains 

 In one respect this is a striking evidence of the impcrfectiori of 

 the geological record, since, but for what may be called a 

 fortunate accident, many of the most interesting inhabitants cf 

 the coal forests might have been altogether unknown to us. 

 On the other hand, it shows how strange and unexpected are 

 the ways in which the relics of the old world have been pre- 

 served for our inspection, and that there is probably scarcely 

 any animal or plant that has ever lived of which some fragment 

 does not exist, did we know where to look for it. 



It may be well to remark, in closing this chapter, how many 

 new forms of life, air-breathing and o^h-wise, make their first 

 appearance in the Carboniferous, and have continued to prevail 

 until now. Here we find the first Amphibians, Scorpions, 

 Spiders, Myriapods, Orthotropous and Coleopterous insects 

 and ten-footed Crustaceans. In the latter group Woodward 

 has recently described the oldest known crab, from the Coal- 

 formation of Belgium. 



