on the rocks. Geology does good service in this matter. It shows us, most clearly and certainly, that these Creative ages were not isolated worlds, but that, severally and unitedly, they constitute one grand chain. of being, or system of life and order. The successive worlds are so inter-connected, so mutually dependent, that each is essential to the plan of the whole. And the conclusion comes home forcibly to the mind of the thoughtful student, that ONE MIND devised, and ONE HAND executed, the whole; and that He must be immutable in His plans and purposes in Creation, because that from the beginning He has fore-arranged and fore-ordered all that was to follow. Does not this consideration give a peculiar emphasis to the words, Thou art the same?' We see it in the rocks, as well as read it in His Word.

'And thy years shall not fail.' How grand comes out this truth, when contrasted with the changes which have passed over all creation since time first began! Just in proportion to the duration of each age, is the

impressiveness of the truth, they shall perish.' And, at the same time, the incomparable grandeur of the thought, 'Thou art the same, and thy years shall not fail.'

There are a few passages which specially relate to the extinction of organic life on the globe. These will next engage our attention.

Now, what are the conclusions to which Geologists have come on this subject? They have found, by careful observation, that, as a rule, the various species of plants and animals have ceased to exist very gradually. They have, for the most part, 'died out.' This result seems to have been brought about in different ways. The most obvious and common have been geographical and climatal changes, caused by the elevation or subsidence of considerable portions of the earth's surface. The effect of such movements has been that large areas have been thereby unfitted for the support of the previously existing fauna and flora, and the way has thus been prepared for the introduction of new

forms of life, adapted to the altered condition of things. It seems, indeed, as if, in addition to the reasons now given, there must be some law of Nature, unknown to us, in obedience to which not only individuals die, but whole species and families of plants and animals become, in the course of time, extinct. Of this mysterious extinction of species, instances are not wanting in our own day. Now, this tendency to 'wax old' and wear out seems evidently alluded to in Hebrews, i. 10-12, as well as in the older and parallel passage in Psalm cii. 25-27.*

To the former of these we have very lately referred as containing a striking allusion to the way in which the successive world-surfaces, having served their time, were 'rolled up,' and put away. The same passage alludes no less clearly to the process of natural decay, and extinction of life, which has characterised the close of the epochs generally. They all shall wax old as doth a garment;' Isaiah thus expresses it in a * Appendix, Note P, p. 242.

passage strictly parallel (li. 6).

The earth shall wax old like a garment, and they that dwell therein shall die in like manner, i.e., slowly and gradually. Thus age, decay, and, eventually, death, are, by the immutable laws of heaven, impressed on all things here below. Earth's most durable structures, her solid hills and mountains, are slowly but certainly yielding to the ravages of time; and the diversified forms of organic life which cover her surface, are obedient to the same laws of decay and death. These laws are, indeed, gradual in their operation, but certain in their final results. The Creator alone knows no change; all things else are passing away.'

But the book of Nature, as we search her stony pages, reveals to us another truth of a diverse kind written therein. Not only do we find the record there of gradual extinction as the normal rule, but there are unmistakable indications of more sudden and violent destruction of life, which has occasionally occurred over extended areas. Descriptions

of such occurrences are to be met with in most of our geological writers.

Dr. Buckland, in his Bridgewater Treatise, i. p. 123, says, 'The cases hitherto examined are examples of the processes of slow and gradual accumulations, in which are preserved the remains of marine, lacustrine, and terrestrial animals that perished during extended periods of time, by natural death. It remains to state that other causes seem to have operated occasionally, and at distant intervals, to produce a rapid accumulation of certain strata, accompanied by the sudden destruction, not only of testacea, but also of the higher classes of the existing inhabitants of the seas.' And a little farther on, referring to the Lias formation, he says, 'Evidence of the fact of vast numbers of fishes and saurians, having met with sudden death and immediate burial, is also afforded by the state of entire preservation in which the bodies of hundreds of them are often found in the Lias.'

Sir R. Murchison, in the Quarterly Jour