of instances—flies off without any further attempt to secure it, and I have then seen the tern sweep back, and, plunging down, retake possession of its booty. Whether, in such cases, the fish was designedly relinquished, in order to be secured again, I cannot say, but here, at any rate, we see another way in which the parasite might come to be outwitted by the more intelligent of its vaches à lait.
These competitions between skua and tern, both of them birds of such swift and graceful flight, are very interesting to watch. The skua, in the midst of the chase, will frequently sweep away, as if it had abandoned all hope, and then return in a wide circling rush, at the end of which there may be a sudden upward shoot, for the tern generally seeks to elude its pursuer by rising higher into the air. Often—and again this is just as with the peewit and gull—a pair of skuas will give chase to the same tern, and then one may see the slender, shining bird quite overshadowed by the two evil figures, as, pressing upon either side, they rise or sink towards it, often almost covering it up with their broad and dusky pinions. Twin evil geniuses they look like, seeking to corrupt a soul, or else dark shadows that this soul itself has summoned up, and that attend it, hardly now to be shaken off:
Da hab' ich viel blasse Leichen
Beschworen mit Wortesmacht.
Sie wollen, nun, nicht mehr weichen
Zurück in die alte Nacht.
For imagination can easily multiply the two into
