having gradually eliminated the source of this danger. But natural selection may have acted in another direction, which would have been still more conducive to the safety of the chick. I observed that the latter—even when, as I judged by its tininess, it had only been quite recently hatched—was as alert and as well able to move about as a young chicken or partridge; but whilst possessing all the power, it appeared to have little will to do so. Its lethargy—as shown by the way in which, even when a good deal older, it would sit for hours without moving from under the mother—struck me as excessive; and it would certainly seem that on a bare narrow ledge, to fall from which would be certain death, chicks of a lethargic disposition would have an advantage over others who were fonder of running about. If we suppose that a certain number of chicks perished even amongst those whose parents always stood between them and the sheer edge, we can understand both the one and the other step towards security having been brought about, either successively or side by side with each other.
From the foregoing it would appear that the young guillemot is fed with fish which are brought straight from the sea in the parent's bill, and not—as in the case of the gulls—disgorged for them after having been first swallowed. It is, however, a curious fact that the fish when thus brought in is, sometimes at any rate, headless. The reason of this I do not know, but with the aid of the glasses I have made quite certain of it, and each time it appeared as though the head had been cleanly cut off. Moreover, on alighting on the ledge the bird always has the fish (a