1 86 THE HAUNTS OF LIFE 



land reptiles, and birds had their origin in 

 land reptiles where then is the marine an- 

 cestry? But the reptiles sprang from an an- 

 cient amphibian stock, whose very name, am- 

 phibian, suggests that they lived partly in 

 water and partly on land. And these am- 

 phibians sprang from fishes, and the original 

 fishes were in the sea. So that when we say that 

 the ancestors of land animals were marine, we 

 usually mean their distant ancestors, belonging 

 perhaps to a much simpler class. On the other 

 hand, when we look at the terrestrial crusta- 

 ceans, called wood-lice or slaters, which we see 

 running about if we turn over loose stones or 

 strip off loose bark, we may safely say these are 

 the direct descendants of sea-slaters, such as 

 we find to-day among the rocks on the shore. 



TELL-TALE EVIDENCES OF MARINE 

 ANCESTRY 



It may be asked, however, why land ani- 

 mals may not have begun their existence on 

 land, instead of being derived from distant 

 ancestors in the sea. This is a good question, 

 which requires a longer answer than is pos- 

 sible here. But part of the answer is this. 



