ON THE ETHIOPIAN PLAINS, night falls at six o'clock. It is impossible to say why this is so. Later we shall discuss this more completely. Examples shall be given. In each case the horizon reddens. Stars appear. The last baboon climbs into his cave. The first hyena emerges from his lair. The diurnal birds--all of them are gray--fall silent. The nocturnal birds begin to sing. These nocturnal birds are brilliantly plumaged, even ornate. Their voices differ from those of the daytime birds. The daytime songs are as harsh as the countryside. They can be heard everywhere, even in the cities. The nighttime songs are seldom heard near human habitation. They are oddly melodious. Such songs can rouse unease. There are stories about some of these songs, and their effects on humans, that may be called incredible. Some of these stories will be discussed. This book may be seen as a discussion of these stories. No one alive today, however, can vouch for them. Perhaps no one alive today has seen a nocturnal bird. They are known, nevertheless, to have iridescent feathers. The eyes of these birds are said to be black and expressionless. These birds are capable of gliding soundlessly for miles. These birds are predators. They are most iridescent when hungry. There are tales of glowing birds carrying off children. We believe these stories are true. Infants vanish during the night. In daylight there is wailing. People gnash their teeth.

THE BIFURCATION OF ETHIOPIA between day and night is virtually absolute. In truth Ethiopia is two countries. It is rare for anyone--any man, any beast--to know them both.