It is impossible to contemplate the effects which followed the great earthquake--the passage of a sea-wave of enormous volume over fully one third of the earth's surface, and the force with which, on the farthermost limits of its range, the wave rolled in upon shores more than ten thousand miles from its starting-place--without feeling that those geologists are right who deny that the subterranean forces of the earth are diminishing in intensity. It may be difficult, perhaps, to look on the effects which are ascribed to ancient earth-throes without imagining for a while that the power of modern earthquakes is altogether less. But when we consider fairly the share which time had in those ancient processes of change, when we see that while mountain ranges were being upheaved or valleys depressed to their present position, race after race, and type after type appeared on the earth, and lived out the long lives which belong to races and to types, we are recalled to the remembrance of the great work which the earth's subterranean forces are still engaged upon. Even now continents are being slowly depressed or upheaved; even now mountain ranges are being raised to a new level, tablelands are in process of formation, and great valleys are being gradually scooped out. It may need an occasional outburst, such as the earthquake of August, 1868, to remind us that great forces are at work beneath the earth's surface. But, in reality, the signs of change have long been noted. Old shore-lines shift their place, old soundings vary; the sea advances in one place and retires in another; on every side Nature's plastic hand is at work modelling and remodelling the earth, in order that it may always be a fit abode for those who are to dwell upon it. [Illustration] THE PHOSPHORESCENT SEA (FROM STUDIES OF ANIMATED NATURE.) BY W.S. DALLAS. [Illustration] It is not merely on land that this phenomenon of phosphorescence is to be seen in living forms. Among marine animals, indeed, it is a phenomenon much more general, much more splendid, and, we may add, much more familiar to those who live on our coasts. There must be many in the British Isles who have never had the opportunity of seeing the light of the glow-worm, but there can be few of those who have frequented in summer any part of our coasts, who have never seen that beautiful greenish light which is then so often visible, especially on our southern shores, when the water is disturbed by the blade of an oar or the prow of a boat or ship. In some cases, even on our own shores, the phenomenon is much more brilliant, every rippling wave being crested with a line of the same peculiar light, and in warmer seas exhibitions of this kind are much more common. It is now known that this light is due to a minute living form, to which we will afterward return.