 After death these sacred bulls, which were distinguished by peculiar marks, had extraordinarily costly obsequies; they were called the risen Ptah, and regarded as the symbol of the soul of Osiris, by whose procreative power all that dies or passes away is brought to new birth and new life--the departed soul of man, the plant that has perished, and the heavenly bodies that have set. Osiris-Sokari, who was worshipped as the companion of Osiris, presided over the wanderings which had to be performed by the seemingly extinct spirit before its resuscitation as another being in a new form; and Egyptian priests governed in the temples of these gods, which were purely Egyptian in style, and which had been built at a very early date over the tomb-cave of the sacred bulls.  And even the Greek ministers of Serapis, settled at Memphis, were ready to follow the example of their rulers and to sacrifice to Osiris-Apis, who was closely allied to Serapis--not only in name but in his essential attributes.  Serapis himself indeed was a divinity introduced from Asia into the Nile valley by the Ptolemies, in order to supply to their Greek and Egyptian subjects alike an object of adoration, before whose altars they could unite in a common worship. They devoted themselves to the worship of Apis in Osiris at the shrines, of Greek architecture, and containing stone images of bulls, that stood outside the Egyptian sanctuary, and they were very ready to be initiated into the higher significance of his essence; indeed, all religious mysteries in their Greek home bore reference to the immortality of the soul and its fate in the other world.