AND HIS COTEMPORARIES. 581 



dressed into exquisite order, eacli successive formation un- 

 folding the record of the organized beings which were then 

 in existence, and to a great extent also the physical condi- 

 tions under which they lived. The series of rocks called 

 Secondary and Tertiary, which are the cemeteries of the 

 Mesozoic and Kainozoic creatures that formed the mid-stages 

 of world-life, have been subjected to a similar course of 

 analysis, and have yielded corresponding results. But the 

 nearer we approach to the existing system, of which man is 

 the head and chief, the more hazy has the prospect been — 

 the more faint and obscure the definition of the outline. 

 The reason is siifficiently obvious. All the great disclosed 

 problems that were most calculated to fascinate the imagina- 

 tion and exercise the intellectual powers lay in the remote 

 past. It was there where the medals were buried, by the 

 interpretation of which the prodigious antiquity of our planet, 

 as a field of life, has been established ; and there, where the 

 vast forces which have rent its coast asunder were, by their 

 effects, most distinctly evinced. There was an irresistible 

 charm in tracing back the firstlings of life to their earliest 

 dawn in the Cambrian and Silurian rocks, and in following 

 the progress upwards from simple to more advanced forms. 

 The Secondary rocks revealed evidence that the surface of 

 our island was formerly clothed with tropical forests, and 

 peopled with Saurian quadrupeds, like the Iguanodon, the 

 Megalosaurus, and the Pterodactyle, which, by their unex- 

 pected forms and colossal proportions, startled the imagina- 

 tion and taxed the synthetic powers of science to restore 

 them. Ascending to the Tertiary series, the genius of Cu- 

 vier worthily followed up by his successors had reproduced 

 the exuberant variety of Mammalian quadrupeds with which 

 the Eocene and Miocene formations teemed. But in the 

 Pliocene strata the exciting interest of novelty waned, till 

 in the newer Quaternary deposits it became nearly evanes- 

 cent. The gravels, sands, and clays, which compose them, 

 were invested with an eminently prosaic character, little 

 promising of food to the imagination, or of profitable exer- 

 cise to the reasoning faculty ; and the treatment they met 

 with was in keeping with their uninviting aspect. They 

 were all summarily disposed of by the convenient and lazy 

 hypothesis of a transitory Diluvian irruption, which had 

 swept over the earth's surface and left them behind. The 

 keen intellect of Agassiz rent the veil of this delusion, and 

 fixed the attention of observers upon the phenomena of 

 glacial action, which for a time brooked no rival, but re- 

 flected a flood of light upon what was before either mistaken 

 or obscure. Like most other fashions, it was in its day su- 



