simpler to more specialised forms. All the discoveries that have been made, and are daily making, never controvert in the least this great order of life; nor do the ablest geologists, though anticipating many new forms, ever expect to find it otherwise with creation than onward and still upward. In this respect the coal-formation takes its place orderly and in perfect harmony with what is known of other formations:-more prolific and more specialised in its forms than the old red sandstone beneath, and less so than the new red and other secondary strata that follow. Looking, in the mean time, at the whole aspects of the carboniferous period, we are reminded (as we have elsewhere* indicated) of geographical conditions never before nor since exhibited on our globe. The frequent alterna tions of strata, and the great extent of our coal-fields, indicate the existence of vast estuaries and inland seas of gigantic rivers and periodical inundations; the numerous coal-seams and bituminous shales clearly bespeak conditions of soil, moisture, and warmth favourable to an exuberant vegetation, and point partly to vegetable drift, and partly to submerged forests, to peat-swamps and jungle-growth; the mountain limestone, with its marine remains, reminds us of low islands fringed with encrinite-banks and coralreefs, and lagoons thronged with shell-fish and fishes; the existence of reptiles and insects tells us of air, and sunlight, and river-banks; the vast geographical extent of the system bears evidence of an equable and continuous climate over a large portion of the earth's surface; while the interstratified trap-tuffs, the basaltic outbursts, and the numerous faults and fissures, testify to a period of intense igneous activity. within the same areas, to repeated upheavals of sea-bottom and submergences of dry land. All this is so clearly indicated to the investigator of the carboniferous system, that *Advanced Text-Book of Geology. he feels as convinced of their occurrence as if he had stood on the river-bank of the period, and seen the muddy current roll down its burden of vegetable drift; threaded the channels of the estuary, gloomy with the gigantic growth of swamp and jungle; or sailed over the shallow waters of its archipelago, studded with reef-fringed volcanic islands, and dipped his oar into the forests of encrinites that waved below. The Permian period, to which we now turn, presents itself more in the light of a new rock-formation than a distinct life-period. Many of its forms are identical with those of the coal period, and we may, without doing great. violence to fact, regard it as the continuation and close of the carboniferous era - specialised by local disturbances in the areas of deposit, and the consequent dying out of many genera and species. Perhaps the most remarkable feature is the rapid disappearance of the coal flora, and its restriction to a few higher forms of tree-ferns and coniferous trees, as if the low swampy jungle had been upheaved into higher and drier lands unfavourable to the growth of 1 1, Palæoniscus Frieslebeni 2, Platysomus striatus sigillaria, calamites, equisetums, and lepidodendra. The gigantic sauroid fishes have also disappeared with the estuaries in which they held supreme sway, though less localised forms, as palæoniscus and platysomus, still occur in abundance; reptiles of larger growth and curious configuration (labyrinthodon) come into view; reptilian and bird-like footsteps (ichnites) can also be traced on the sandstones; and if American geologists be not mistaken, manımalian life in its lowly marsupial form (dromatherium) now comes for the first time on the stage of being. On the whole, however, Jaw of Dromatherium silvestre, from the Red Sandstones there seems a paucity of life during the Permian period, when compared with that which preceded it; and this we may, in the mean time, ascribe partly to geographical changes in the distribution of sea and land, partly to the altered composition of the sea-water in certain areas where we have now magnesian limestones and red ferruginous sandstones, and partly to that change of climate which is indicated by the symptoms of glacial action in the formation of its conglomerates and bouldery breccias.* * Professor Ramsay, who was the first to advocate, in a decided manner, the glacial origin of these breccias, founds his belief on the following evidences-1. The great size of many of the fragments-the largest observed weighing (by a rough estimate) from a half to three-quarters of a ton. 2. Their forms. Rounded pebbles are exceedingly rare. They are angular or sub-angular, and have those flattened sides so peculiarly characteristic of many glacier-fragments in existing moraines, and also of many of the stones of the pleistocene drifts, and the moraine matter of the Welsh, Highland, Irish, and Vosges glaciers. 3. Many of them are highly polished, and others are grooved and finely striated, like the stones of existing Alpine glaciers, and like those of the ancient We now close the long record of Ancient Life, during which whole races and families departed, and others took their place the march of vitality being ever forward to higher and higher orders. We have seen that all the great types of life — radiate, molluscan, articulate, and vertebrate-had their beginning simultaneously and independently on the globe, and that all subsequent progress has been restricted to the modification and elimination of these primal patterns. We have seen the graptolites of Siluria rise, culminate, and depart with that period; seen also its curious encrinites and foot-stalked sea-urchins, or cystideæ, flourish and die within the same limits; and witnessed its wonderful flush of trilobite life, which waned in the old red, and finally disappeared about the middle of the carboniferous era. So also have we witnessed the larger crustacean forms of eurypterus and pterygotus come strongly and forcibly on the Devonian stage, and somewhat speedily wane and die out with the coal period, during which other forms, prefigurative as it were of the existing limulus, take their places. In like manner the curious bone-clad fishes of the old red (the "palichthyan" aspect of fish life) rise and depart with that system-only a few of the genera, but none of the species, living into the carboniferous epoch. And when we come to the coal period itself, there also all the wonderful and exuberant forms of its vegetation-its stigmaria, sigillaria, lepidodendra, bothrodendra, calamites, and tree-ferns-start into being, flourish in profusion, and depart with those physical peculiarities which stamped glaciers of the Vosges, Wales, Ireland, and the Highlands of Scotland; or like many stones in the pleistocene drifts. 4. A hardened cementing mass of red marl, in which the stones are very thickly scattered, and which in some respects may be compared to a red boulder-clay, in so far that both contain angular, flat-sided, and striated stones, such as form the breccias wherever they occur.-Journal of Geological Society, vol. xi. their impress on the life of that era. So also with its sauroid fishes; and so also with many genera and species of its shell-fish and corals and encrinites, which though more lowly are nevertheless peculiarly distinctive of carboniferous seas, and are never found in the waters of subsequent ages. From the first to the last-from the Silurian to the Permian-all has been growth and decay, and in that death a progress which ever goes forward without halt or hesitation. No indecision; no trial-work; no error to be corrected ; no blunder to be revised. And yet amid all this incoming and outgoing, as we shall see in the following chapter, there has been no break in vitality, no change of the great primal patterns, but merely such modifications as best harmonise with the new conditions of each succeeding era. Nor must we regard this harmony between geographical condition and organic manifestation in any other light than that of a mere co-adaptation; for over and above it there is clearly a prescient design, having respect to development in time from more general to more specialised types, and from physiological simplicity to physiological complexity of functions. From the obscure and simple forms of the lowest stratified systems we rise stage after stage to higher and higher manifestations of life; onwards and still upwards is the orderly course of creation; and yet in this vast and varied progression every member is bound to that which preceded it, as well as to that which accompanies it, by the ties and relationship of one great cosmical plan. This is surely more than mere physical development"- something higher than the "transmutation of specific forms under the force of external conditions"-something more precise and definite than "natural selection in the struggle for existence," or any other of the materialistic hypotheses 66 H |