GEOLOGY. 551 



CHAPTER IV. 



SECONDARY EPOCH. 



IN this epoch everything strongly contrasted with that 

 which preceded it. In the latter the vegetable kingdom 

 predominated during its whole course to an extraordinary 

 extent ; in this the animal kingdom seems to have absorbed 

 all the vital forces of the globe. 



The secondary strata were peopled by a fauna altogether 

 new, and more and more exuberant. The reptiles astonish 

 us by their number, their gigantic size, and their unwonted 

 forms, antique and incomprehensible inhabitants of the 

 globe, reproduced in all their parts to our wondering eyes 

 by the genius of a Cuvier and an Owen ! It is to this epoch 

 that the name of the Reptilian Age may be most appropri- 

 ately given, so completely did these creatures then pre- 

 dominate on the globe ; it was the age of the Ichthyosauri, 

 the Plesiosauri, and the Mosasauri, a throng of frightful 

 lizards, compared to which our own are mere pigmies, arid 

 which spread terror through the antediluvian seas. 



At this period we see innumerable molluscs, the shells of 

 which have been carefully preserved by the rocks. Some 

 belong to genera which are no longer met with in our pres- 

 ent seas ; all to species which are absolutely unknown at 

 the present day. 



Already, at the time we speak of, the previous extreme 

 heat of the earth had declined. The sky had grown clearer, 

 and the atmosphere become less heavy ; still there was 



