gigantic race. It is at least curious that while in the fifth day great reptiles like those of the secondary rocks form the burden of the work, in the sixth we have a term which so directly reminds us of those gigantic pachyderms which figure so largely in the tertiary period. Large carnivora also occur in the tertiary formations, and there are some forms of reptile life, as, for example, the serpents, which first appear in the tertiary. I may refer to any popular text-book of geology in evidence of the exact conformity of this to the progress of mammalian life, as we now know it in detail from the study of the successive tertiary deposits. The following short summary from Dana, though written several years ago, still expresses the main features of the case: "The quadrupeds did not all come forth together. Large and powerful herbivorous species first take possession of the earth, with only a few small carnivora. These pass away. Other herbivora with a larger proportion of carnivora next appear. These also are exterminated; and so with others. Then the carnivora appear in vast numbers and power, and the herbivora also abound. Moreover these races attain a magnitude and number far surpassing all that now exist, as much so indeed, on all the continents, North and South America, Europe, Asia, Africa, and Australia, as the old mastodon, twenty feet long and nine feet high, exceeds the modern buffalo. Such, according to geology, was the age of mammals, when the brute species existed in their greatest magnificence, and brutal ferocity had free play; when the dens of bears and hyenas, prowling tigers and lions far larger than any now existing, covered Britain and Europe. Mammoths and mastodons wandered over the plains of North America, huge sloth-like Megatheria passed their sluggish lives on the pampas of South America, and elephantine marsupials strolled about Australia. "As the mammalian age draws to a close, the ancient carnivora and herbivora of that era all pass away, excepting, it is believed, a few that are useful to man. New creations of smaller size peopled the groves; the vegetation received accessions to its foliage, fruit-trees and flowers, and the seas brighter forms of water life. This we know from comparisons with the fossils of the preceding mammalian age. There was at this time no chaotic upturning, but only the opening of creation to its fullest expansion; and so in Genesis no new day is begun, it is still the _sixth day_."