Many birds show that they have the power of not only cleverly adapting themselves to circumstances in matters concerning their nesting, but that they are also equal to unforeseen accidents, which not unfrequently occur. From the secluded haunts and hideling habits of birds of the rail kind, it would hardly be imagined that they were endowed with much intelligence. Here is a striking instance, however, to the contrary. A pair of waterhens built their nest upon an ornamental piece of water of considerable extent, which was ordinarily fed from a spring, and into which another large pond was occasionally emptied. This upon one occasion was done while the female was sitting, and, as the nest had been built at low water, the sudden influx from the second pond caused the water to rise so rapidly as to threaten the destruction of the eggs. This the birds seemed aware of, and immediately took precautions against it. The gardener on the estate, knowing of the sudden rise of water, went to look after the nest, though quite expecting to find the eggs ruined. Instead of this he saw both birds busily engaged about the nest, and adding, with all possible despatch, fresh materials to the fabric to bring it above the impending flood. This they not only succeeded in doing, but it was observed that upon the first rush of water they had removed the eggs to a distance of some feet from the margin of the pool. In the meantime the nest rose rapidly in height, and when the water began to retire the eggs were brought back and placed in the nest. In a few days these were hatched, and the young were swimming with their parents about the pool. The nest plainly showed the formation of the old and new material, and testified to the instinct or reason of the bird architects. In this connection birds have been known to adapt their nests to changed forms of architecture; and almost innumerable little devices may be seen in individual nests tending to their special safety or protection. As an instance of adaptation to haunt it may be mentioned that in the north, buzzards and ravens invariably nest among the rocks of the crags, whilst in the south their nests are just as invariably found in trees.