Again, to the Egyptian mind, incapable of abstract thought, an immaterial and intangible deity was an impossible conception. A god, and more so by reason of his godhead, must manifest and function in an actual body. The king was believed to be an incarnation of a god, but he was apart and only one, and as the Egyptian everywhere craved the manifestation of and communion with his gods, it thus came about that incarnations of deity and its many attributes were multiplied. Certain animals could represent these to a greater degree than man, though of course to Egyptian thought man was the standard by which all in the universe was to be measured and weighed. The gods were but little greater than men; they were limited, and might know death. Their immortality was only acquired by the power of transmigration from one body to another, escaping human death by transference to successive forms and a renewal of the life force. The symbolism of the Egyptian religion is mostly expressed by means of animals. Thus the god of the dead is spoken of as a jackal, the water-god as a crocodile, while the sky is a cow, the sun a falcon, the moon an ibis. Because of this exaltation of certain animals whole species were held as sacred, and this led to the many strange ideas and customs amongst the Egyptians mentioned so often by classic writers, as, for instance, considering a man fortunate who was eaten by a crocodile. When these animals died their owners mourned as for a relative, and the greatest care was taken in the disposal of their remains. Cows were held in such veneration that their bodies were cast into the sacred waters of the Nile, and a bull was buried outside the town, its horns protruding above the ground to mark the place of interment. Other instances might be adduced. Apis From the earliest times the bull was worshipped in Egypt as the personification of strength and virility and might in battle. Manetho traces the cult of Apis to Kaiekhos, a king of the Second Dynasty, who appointed a chosen bull, Hap, to be a god; but Ælian ascribes this to Mena, the first historical king of Egypt. Much of our knowledge concerning this cult is derived from Greek sources. Herodotus gives the following description of Apis: "He is the calf of a cow which is incapable of conceiving another offspring, and the Egyptians say that lightning descends upon the cow from heaven and that from thence it brings forth Apis. This calf has the following marks: it is black and has a square spot of white on the forehead; and on the back the figure of an eagle; and in the tail double hairs, and on the tongue a beetle."