Another point which Mr. Miller has labored hard to establish, and of which there seems to be no reasonable doubt, is, that in many families of animals, not only were the first species that appeared of high organization, but there was a gradual degradation among those that were created afterwards. Of the fishes generally, he says, that "the progress of the race, as a whole, though it still retains not a few of the higher forms, has been a progress, not of development from the low to the high, but of degradation from the high to the low." Again he says, "We know, as geologists, that the dynasty of the fish was succeeded by that of the reptile; that the dynasty of the reptile was succeeded by that of the mammiferous quadruped; and that the dynasty of the mammiferous quadruped was succeeded by that of man, as man now exists--a creature of a mixed character, and subject, in all conditions, to wide alternations of enjoyment and suffering. We know further,--so far, at least, as we have succeeded in deciphering the record,--that the several dynasties were introduced, not in their lower, but in their higher forms; that, in short, in the imposing programme of creation, it was arranged as a general rule, that in each of the great divisions of the procession the magnates should walk first. We recognize yet further the fact of degradation specially exemplified in the fish and the reptile." "Among these degraded races, that of the footless serpent, which _goeth upon its belly_, has long been noted by the theologian as a race typical, in its condition and nature, of an order of hopelessly degraded beings, borne down to the dust by a clinging curse; and curiously enough, when the first comparative anatomists in the world give _their_ readiest and most prominent instance of degradation among the divisions of the natural world, it is this very order of footless reptiles that they select." Among the invertebrate animals are numerous examples of the deterioration of a race. M. Alcide D'Orbigny, one of the most accomplished of living paleontologists, in his _Cours Elementaire de Paleontologie et de Geologie_, speaks as follows of the cephalopods found in the oldest rocks: "See, then, the result; the cephalopods, the most perfect of the mollusks, which lived in the early period of the world, show a progress of degradation in their generic forms. We insist on this fact relative to the cephalopods, which we shall hereafter compare with the less perfect classes of mollusks, since it must lead to the conclusion that the mollusks, as to their classes, have certainly retrograded from the compound to the simple, or from the more to the less perfect."