Now we have already mentioned that in the Mithra cult the slaying of a Bull by the Sungod occupies the same sort of place as the slaving of the Lamb in the Christian cult. It took place at the Vernal Equinox and the blood of the Bull acquired in men's minds a magic virtue. Mithraism was a greatly older religion than Christianity; but its genesis was similar. In fact, owing to the Precession of the Equinoxes, the crossing-place of the Ecliptic and Equator was different at the time of the establishment of Mithra-worship from what it was in the Christian period; and the Sun instead of standing in the He-lamb, or Aries, at the Vernal Equinox stood, about two thousand years earlier (as indicated by the dotted line in the diagram), in this very constellation of the Bull. (1) The bull therefore became the symbol of the triumphant God, and the sacrifice of the bull a holy mystery. (Nor must we overlook here the agricultural appropriateness of the bull as the emblem of Spring-plowings and of service to man.) (1) With regard to this point, see an article in the Nineteenth Century for September 1900, by E. W. Maunder of the Greenwich Observatory on "The Oldest Picture Book" (the Zodiac). Mr. Maunder calculates that the Vernal Equinox was in the centre of the Sign of the Bull 5,000 years ago. (It would therefore be in the centre of Aries 2,845 years ago--allowing 2,155 years for the time occupied in passing from one Sign to another.) At the earlier period the Summer solstice was in the centre of Leo, the Autumnal equinox in the centre of Scorpio, and the Winter solstice in the centre of Aquarius--corresponding roughly, Mr. Maunder points out, to the positions of the four "Royal Stars," Aldebaran, Regulus, Antares and Fomalhaut. The sacrifice of the Bull became the image of redemption. In a certain well-known Mithra-sculpture or group, the Sungod is represented as plunging his dagger into a bull, while a scorpion, a serpent, and other animals are sucking the latter's blood. From one point of view this may be taken as symbolic of the Sun fertilizing the gross Earth by plunging his rays into it and so drawing forth its blood for the sustenance of all creatures; while from another more astronomical aspect it symbolizes the conquest of the Sun over winter in the moment of "passing over" the sign of the Bull, and the depletion of the generative power of the Bull by the Scorpion--which of course is the autumnal sign of the Zodiac and herald of winter. One such Mithraic group was found at Ostia, where there was a large subterranean Temple "to the invincible god Mithras."