The argument is a very simple one. Of all the vertebrata, fishes rank lowest, and in geological history appear first. We find their remains in the Upper and Lower Silurians, in the Lower, Middle, and Upper Old Red Sandstone, in the Mountain Limestone, and in the Coal Measures; and in the latter formation the first reptiles appear. Fishes seem to have been the master existences of two great systems, mayhap of three, ere the age of reptiles began. Now fishes differ very much among themselves: some rank nearly as low as worms, some nearly as high as reptiles; and if fish could have risen into reptiles, and reptiles into mammalia, we would necessarily expect to find lower orders of fish passing into higher, and taking precedence of the higher in their appearance in point of time, just as in the _Winter's Tale_ we see the infant preceding the adult. If such be not the case--if fish made their first appearance, not in their least perfect, but in their most perfect state--not in their nearest approximation to the worm, but in their nearest approximation to the reptile--there is no room for progression, and the argument falls. Now it is a geological fact, that it is fish of the higher orders that appear first on the stage, and that they are found to occupy exactly the same level during the vast period represented by five succeeding formations. There is no progression. If fish rose into reptiles, it must have been by sudden transformation--it must have been as if a man who had stood still for half a lifetime should bestir himself all at once, and take seven leagues at a stride. There is no getting rid of miracle in the case--there is no alternative between creation and metamorphosis. The infidel substitutes progression for Deity; Geology robs him of his god.