Here, after presently stripping to the elbow, you may surprise a hermit-crab, or catch the spotted “goby” in his dark saline pool, but please let him go again; you ought to give him his freedom, if only out of gratitude; for all this time your own tired body is being braced and refreshed, and your mind, yesterday jaded and careworn, is winning back its elasticity under a sense of blessed repose. I will now mention some peculiarities in the nature of our beaches, which I have noted from time to time in the book of my experience. * * * * * A BEACH is supposed to be a permanent accumulation of pebbles and small shingle, due to such cliffs or banks as are near at hand. And this general definition would be so far scientifically correct, if nature were stagnant like the surface of a deserted mill-pond. But, as Nature is always at work, always shifting the scenes, the above definition, although it sounds like a truism, does not hold good in either of its clauses. The accumulation which we look upon is _not_ permanent, nor is it always due to a neighbouring source. Sometimes the collection of stones which we find heaped up in an immemorial bay has been washed round—much of it, perchance, recently—from a distant quarter. And this might be taking place under our very eyes, and we not know it, just as we do not _see_ the grass grow. Except in very calm weather, beaches are continually travelling, and they travel rapidly along certain lines of coast, until they arrive at a terminal point or headland. To get round this latter takes time, but they do get round it at last, with the help of strong gales prevailing in one direction, and under the rushing tides of an equinox. Now if we suppose a few acres of shingle to be once fairly carried past such a promontory, and discharged into the curve of an elliptical bay, they will be locked in, and may, perhaps, never get out again. I have myself no doubt that Sandown Beach is fed and replenished in this manner: and the bay being deeply indented with the points of Culver and Dunnose, prominent at opposite extremities, egress is difficult. Yet most persons might naturally suppose that whatever they find on the beach here is due to its overhanging cliffs. Some of the best pebbles travel fast, and are, in fact, migratory, till they reach such a “nidus” as I have described. This is owing to the rounded form which fossils usually assume. Angular lumps rather remain stationary. Jasper I suppose makes few excursions: while the agates and oval choanites are continually on the move, and may have visited a dozen different localities before they are picked up. I have hunted a bit of yellow agate in this way for above a mile in the course of a few weeks, dropping it again on purpose, and never finding it in the same place. Beside the above real motion of a beach, there is an apparent total change for a time which is by no means uncommon in exposed situations.