The kriya yogi mentally directs his life energy to revolve upward and downward, around the six spinal centres (medullary, cervical, dorsal, lumbar, sacral, and coccygeal plexuses) which correspond to the twelve astral signs of the zodiac, the symbolic Cosmic Man. One-half minute of revolution of energy around the sensitive spinal cord of man effects subtle progress in his evolution; that half-minute of kriya equals one year of natural spiritual unfoldment.
