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220 foamed in again. The sea boils in about the rocks off these iron shores in a tremendous manner, even when, like to-day, it is quite calm. On the stillest day, indeed, there is often a sullen swell which makes varying patches and long chequered lines of foam all around them. The sea never sleeps in these islands—only slumbers uneasily like some terrific monster that anything may awake.

It is observable that some of these sea-pies are bolder than others in outstanding the swell of the waves. Some flee it before it comes, others fear not to have it wet their feet, whilst others, again, will almost risk being soused in it. But are these different birds, or are they all different at different times? On that, of course, must depend whether a process of differentiation, on evolutionary lines, is in action amongst them or not. For myself, I think the first, and that, from waders or paddlers, some of these birds may in time become swimmers—which would make them a sort of sea moorhen. The redshanks has gone farther in this direction, for he sometimes swims, but I know of no intermediate form, no sea and sea-shore bird corresponding to our moorhen or coot.—Mussels, then, and the beak thrust in amongst seaweed; but no limpets up to the present. Now limpets, as I said before, are all over the rocks, and so need no searching for. Why so chary, then, if the birds really affect them?