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Amphibians, or the Carboniferous; IV. the Age of Reptiles, including the periods between the Coal and the Tertiary; V. the Age of Mammals, or the Tertiary and Post-Tertiary; VI. the Age of Man. The progress of Vegetable Life affords: first, the Age of Algæ or Sea-weeds, corresponding to the Silurian and Devonian ; second, the Age of Flowerless Trees (Acrogens) and Coniferæ, or the age of Coal-Plants; third, the Age of Dicotyledonous Plants, or our common trees (oaks, elms, etc.), beginning just before the age of Mammals.
XII. A gradual elevation of the successive races involved in the gradual refrigeration of the earth, as also in its other steps of physical progress. The whole plan of creation had evident reference to man as the end and crown of the Ani. mal Kingdom, and to the present cool condition of the globe, as, therefore, its most exalted state. It is hence obvious, that progression in the earth from a warmer to a cooler condition, necessarily involved progression from the lower to the higher races, such as actually took place. This cooling, therefore, implied almost necessarily the complete extinction of some earlier races, fitted for earlier time, as well as of species. The whole fifth day (using the term in Genesis) until its later epochs, was a time of warm climate from the equator to the poles. Not a species of the thousands in those ages now exists. Species and genera appeared and disappeared as time moved on: the last trilobite lived in the Carboniferous seas, and the last Lepidodendra in the forests of the Carboniferous continents; the last ammonite, flying reptile and swimming saurian existed in the Reptilian age, when molluscs as well as reptiles passed their prime, both as to numbers of individuals and rank of species. Even the fishes bear distinctly, in their bodies, the marks of the particular part of the fifth day in which they lived : for they first appear in the Devonian age with the spinal column elongated quite to the extremity of the upper lobe of the tail; and afterwards it becomes less and less elongated until the middle of the Reptilian age, when, for the first time, species occur with the body cut off square behind, as in existing species; moreover, the old type of tail disappears, and almost VOL. XIII. No. 49.
completely too the Ganoid tribe of fishes, in which it was so striking a characteristic. Thus the world took its successive steps onward, towards the Golden Age, in the then distant future. The earlier races were of lower types, not because the Creative Hand was weak, but for the reason that the times, that is the temperature and condition of the globe, were just fitted, in each case, for the races produced, and the progress of the plan of creation, correspondingly, required it.
As between the hot equator and the frigid zones, tribes now have their limits in geographical distribution, so in geological time, between the warm Silurian age and the cool present, there was a localization of groups in time, a chronological distribution,-an increase and period of maximum at different epochs along the Ages. The Reptilian and Molluscan types attaining their maximum in the Reptilian age, are examples. A few genera reach from the very first dawn of life to the existing period: they are continuous lines, binding creation in one. This oneness also appears most strikingly in the fact that hardly a fragment of a fossil is taken from the oldest rocks that is not at once as well understood as if it were from an existing species.
The intervals of rest in "self-existent" nature, which Professor Lewis speaks of, are not in the records of the earth. The longest suspension of life in North America took place, as nearly as we can learn, between the Coal period and the Middle Reptilian. Moreover, the epochs of revolution in Europe and America were, in general, not contemporaneous; and this implies merely a non-contemporaneity in the convulsions or oscillations of the earth's crust in the two hemispheres.
XIII. System of life-evolution. The facts gathered from nature teach us :
1. That species have not been made out of species by any process of growth or development; for the transition-forms do not occur.
2. That the original divine power" did not create a generic or universal germ from which all subordinate genera and species were developed; for, with any such system of
evolution, the Creator would have been incompetent to complete the creation begun; each revolution would have frustrated every new effort.
3. That the evolution or plan of progress, was by successive creations of species, in their full perfection. After every revolution, no imperfect or half
made forms occur; no backstep in creation ; but a step forward, through new forms, more elevated in general than those of earlier time.
4. That the creation was not in a lineal series from the very lowest upward. The four sub-kingdoms of animal-life, the Radiate, Molluscan, Articulate, and Vertebrate, peared in some of their representatives ; and the first three almost or quite together. The types are wholly independent, and are not connected lineally, either historically or zoologically ; and this is a general principle with regard to subordinate groups. The earliest species of a class were often far from the very lowest, although among the inferior. The gigantic saurians appeared before turtles and serpents; trilobites were superior to many crustaceans afterwards created; and the fish that began the Vertebrata, were powerful species, even superior in attributes of life, though not in type, to some existing Amphibians.
5. That the creation of life was the unfolding of a plan, which involved distinct archetype enactments, and, subordinate to these, and in harmony with them, expressions of purposes or ideas of a less and less general character. The four sub-kingdoms of animal life were the four archetype enactments: they limited the development of the animal creation to these four directions; and every new group came forth in subordination to these established types. So the subordinate groupings, classes, tribes, etc., have the same relation to the groups under them.
6. That the development of the plan of creation, while by successive creations, was in accordance with the law of evolution, as Agassiz has explained, that is, progress from the simple to the complex, from comprehensive unity to multiplicity through successive individualizations. The institution of the Vertebrate type in the memberless fish, embraced in
its idea all those parts and organs, external and internal, which were afterwards brought out, and which have their highest individualization, in man; so that in the bony structure, for example, we may trace the homologies between the human skeleton and the primitive fish-type. The unfolding was, in some groups, a general rising in grade, until the time of maximum, as in the Reptilian type; but embraced expansions both upward and downward, that is, to superior and inferior tribes. In many cases, the original or earliest group was but little inferior to those of later date, and the progress was towards a purer expression of the type. Thus the earliest fishes had reptile teeth, a bony coat of mail, and other reptilian characteristics, foreshadowing the Reptile type af. terwards introduced. In the unfolding of the type, the reptilian features were lost, the ancient race became almost wholly extinct, and gradually the fish type came out in its purity and full diversity. This is one of numerous examples of this kind.
The Molluscan type was unfolded, in all its grand divisions in the Silurian or Molluscan age. The Articulate type, on the contrary, appeared then only in the inferior waterspecies, crustaceans and worms; and gradually, as time moved on, one grand division after another was evolved, until the age of Man, the period of their greatest diversity. A reason for this difference consists in the fact that Articulates are, like Vertebrates, largely land species. Moreover, every new diversity of climate, soil, plant, or animal, enlarged the field for insect life.
7. That hypotheses as to the precise mode of creating a species are presumptuous. D’Orbigny, a distinguished geologistof France, in his Geology (1851, vol. II., p. 251), says well:“Quelle est la force créatrice qui a eu cette toute-puissance si extraordinaire ? Ici nous devons confesser l'impossibilité complète dans laquelle nous trouvons de répondre à aucune de ces hautes questions. Il est des limites que l'esprit humain ne peut franchir, des circonstances ou l'homme doit s'arrêter et se borner à admettre les faits qu'il ne peut expli
XIV. The revolution closing the Reptilian age in geology a universal one. Although the catastrophes in the earth's history were seldom universal, that closing the Reptilian age swept both Europe and America alike, and, as far as we know, the whole earth. Its destruction of the life of the Cretaceous period (the last of the Reptilian age) was complete, with scarcely an exception. Thus geology and the Bible both mark the close of the fifth day. After such a devastation, the new creation began, that of Mammals or quadrupeds: not, be it understood, of Mammals alone, for all the lower tribes had their various representatives also, by the same creation, from molluscs and corals to fish and reptiles. All, by their new forms, express the character of the age. The climates of the earth, as this age of Mammals opened, were, for the first time, widely diversified; yet the facts show that they were not as cool as now, until the age had half elapsed.
XV. The creation of Mammals introducing a new element into the world. The type of animal life which began with this
age, the sixth day, was that in which the earth was to reach its highest destiny. It was the full establishment of that special type of Vertebrates that was at last to be exalted by the endowment of a soul; that, in which the mutual dependence of the parent and young, indicated in the term mammalia, is its grand feature, the principal means, in this age of Man, of cultivating those affections which bind soci. ety together and man to his Maker. There is hence the highest beauty and philosophy in the Mosaic record, independent of its historical facts, in thus separating the Mammals from the other Vertebrates.
Some small insect-eating Mammals appeared in the age of Reptiles. They were few (four species have been found) and weak, in striking contrast with the huge Saurians that filled the seas, earth, and air in that age. They have been well called prophetic types, announcements, as has been already explained of the true age of Mammals next to open in its full grandeur. Such seeming exceptions are in fact