198 THE SECONDARY AGES. 



life the former teeming with foraminifera, sponges, corals, 

 encrinites, starfishes, shell-fish of every order, fishes and rep- 

 tiles ; and the latter with gigantic ferns, reed-like grasses, 

 cycads, zamias, palms, and pine-trees, which "became the 

 chosen food or shelter of numerous insects, of reptiles ter- 

 restrial, arboreal, and aerial, of birds, and of marsupial mam- 

 mals. What a busy panorama of life, growth, and decay is 

 presented by these secondary ages ! And not alone mere 

 growth and decay, but development and progress j for dur- 

 ing the long periods that elapsed between the commence- 

 ment of the Trias and the close of the Chalk, thousands of 

 forms became extinct newer and higher ones taking their 

 places, and at every stage approaching nearer and nearer to 

 those of the Tertiary and Current epochs. So perceptible 

 indeed is this approach that it has been proposed to arrange 

 the geological formations into two great divisions only the 

 palceozoic, embracing all to the close of the Permian ; and 

 the neozoic, all from the commencement of the Trias up to 

 the present day. But whatever may be the value of such 

 arrangements, the fact of progression is everywhere obvious 

 so obvious, that even the non-scientific observer could 

 have little difficulty in distinguishing between the fossil 

 forms of the primary and secondary ages. 



Let those who refuse their assent to a plan of vital devel- 

 opment only study for a day or two the magnificent collec- 

 tion of secondary fossils in our National Museum, or even 

 peruse their figures as given in ordinary geological works ; 

 and if at all capable of comparing, they cannot fail to per- 

 ceive the vast advance that has been made upon the primary 

 or palaeozoic forms. Not only is there the introduction of 

 birds and mammals formerly unknown, but the stamp im- 

 pressed upon all the lower orders corals, molluscs, crus- 

 tacea, fishes, and reptiles is that of greater complexity 

 and specialisation. Let them next compare them with ter- 



