is simple: there is no averting of a collision! But the collision is executed in a remarkable way: the two birds, when close to each other, leap up from the water and meet breast to breast, almost vertical, suddenly revealing the whole flashing white under-surface. They keep themselves in this position by violent splashings of the feet, rocking a little from side to side as if dancing, and very gradually sinking down (always touching with their breasts) towards the horizontal. Meanwhile, they exchange some of the weed they are carrying; or at least nibbling and quick movements of the head are going on. And so they settle down on to the water, shake their heads a few times more, and separate, changing back from these performers of an amazing age-old rite--age-old but ever fresh--into the feeding- and sleeping-machines of every day, but leaving a vision of strong emotion, canalized into the particular forms of this dive and dance. The whole performance impresses the watcher not only with its strength, but as being apparently of very little direct (though possibly much indirect) biological advantage, the action being self-exhausting, not stimulating to further sexual relations, and carried out, it would seem, for its own sake. Further acquaintance with the Grebe only deepened the interest and made clearer the emotional tinge underlying all the relations of the sexes. This bird, too, has its “greeting ceremony”; but since, unlike the colonial Herons and Egrets, it makes every effort to conceal its nest, this cannot take place at its most natural moment, that of nest-relief, but must be made to happen out on the open water where there are no secrets to betray. If the sitting bird wishes to leave the nest, and the other does not return, it flies off, after covering the eggs with weed, in search of its mate; it is common in the breeding season to see a Grebe in the “search-attitude,” with neck stretched up and slightly forward and ear-tufts erected, emitting a special and far-carrying call. When this call is recognized and answered, the two birds do nothing so simple as to fly or swim to each other, but a special and obviously exciting ceremony is gone through. The bird that has been searched for and found puts itself into a very beautiful attitude, with wings half-spread and set at right angles to the body, ruff erected circularly, and head drawn back upon the shoulders, so that nothing is visible but the brilliant rosette of the spread ruff in the centre of the screen of wings, each wing showing a broad bar of brilliant white on its dusk-grey surface. In this position it swings restlessly back and forth in small arcs, facing towards its mate. The discoverer meanwhile has dived; but, swimming immediately below the surface of the water, its progress can be traced by the arrowy ripple it raises. Now and again it lifts its head and neck above the water, periscope-wise, to assure itself of its direction, and resumes its subaqueous course.