Sagittarius, the Zodiacal sign is a symbol of the ninth period of the cycle of Life in which the lower mind is perfected through evolution and therefore "dies". The Higher Self seated on the intelligence (Horse) destroys with the "arrow" of the Spirit the lower qualities, thus enabling the lower consciousness to rise to the Higher Mind. The number 3 is the number of perfection and completeness. 9 which is 3 squared, refers to the attainment of perfection on the 3 lower planes. For 9 periods the Life of the Logos ensouled the manifesting egos on the mental plane, but at the 10th period the personality is evolved sufficiently to enable the lower qualities to assemble. The NINE GATES OF THE BODY, physiologically are the nine openings of the body, six above 9eyes, ears and nostrils) and three below (mouth and two vents). They are intimately related with etheric, astral and mental centres and activities, with which they correspond on the several planes of the Soul. These centres and their connections are mentioned under the symbols of "nine brothers", "nine streets", etc. There are 18 centres of organization in the soul, on various planes. 6+6+6=18=Osiris Khenti Amenta "In the uppermost part of the settlement make nine bridges, in the middle six, and in the lowermost part three." --Vendidad, S.B. of E. The Nine Bridges are the nine centres on the higher planes, whose correspondences find representation on the lower planes. The six middle centres are astral centres and the three lowermost centres are etheric.