12. Among these are two of especial celebrity, Meroe and Delta. The latter derives its name from its triangular form like the Greek letter; but when the sun begins to pass through the sign of Cancer, the river keeps increasing till it passes into Libra; and then, after flowing at a great height for one hundred days, it falls again, and its waters being diminished it exhibits, in a state fit for riding on, fields which just before could only be passed over in boats.
13. If the inundation be too abundant it is mischievous, just as it is unproductive if it be too sparing; for if the flood be excessive, it keeps the ground wet too long; and so delays cultivation; while if it be deficient, it threatens the land with barrenness. No landowner wishes it to rise more than sixteen cubits. If the flood be moderate, then the seed sown in favourable ground sometimes returns seventy fold. The Nile, too, is the only river which does not cause a breeze.
14. Egypt also produces many animals both terrestrial and aquatic, and some which live both on the earth and in the water, and are therefore called amphibious. In the dry districts antelopes and buffaloes are found, and sphinxes, animals of an absurd-looking deformity, and other monsters which it is not worth while to enumerate.
15. Of the terrestrial animals, the crocodile is abundant in every part of the country. This is a most destructive quadruped, accustomed to both elements, having no tongue, and moving only the upper jaw, with teeth like a comb, which obstinately fasten into everything he can reach. He propagates his species by eggs like those of a goose.
16. And as he is armed with claws, if he had only thumbs his enormous strength would suffice to upset large vessels, for he is sometimes ten cubits long. At night he sleeps under water; in the day he feeds in the fields, trusting to the stoutness of his skin, which is so thick that missiles from military engines will scarcely pierce the mail of his back.
17. Savage as these monsters are at all other times, yet as if they had concluded an armistice, they are always quiet, laying aside all their ferocity, during the seven days of festival on which the priests at Memphis celebrate the birthday of Apis.
18. Besides those which die accidentally, some are killed by wounds which they receive in their bellies from the dorsal fins of some fish resembling dolphins, which this river also produces.
19. Some also are killed by means of a little bird called the trochilus, which, while seeking for some picking of small food, and flying gently about the beast while asleep, tickles its cheeks till it comes to the neighbourhood of its throat. And when the hydrus, which is a kind of ichneumon, perceives this, it penetrates into its mouth, which the bird has caused to open, and descends into its stomach, where it devours its entrails, and then comes forth again.
20. But the crocodile, though a bold beast towards those who flee, is very timid when it finds a brave enemy. It has a most acute sight, and for the four months of winter is said to do without food.
21. The hippopotamus, also, is produced in this country; the most sagacious of all animals destitute of reason. He is like a horse, with cloven hoofs, and a short tail. Of his sagacity it will be sufficient to produce two instances.