Six seven, the three Yang Meridians decline above, the face is withered, and hair begins to turn white. Seven seven, the Ren Meridian is deficient, the Thoroughfare Vessel weakens, heavenly water is exhausted, and earthly pathway is blocked, hence the body deteriorates and is childless. At eight, the boy's kidney Qi is solid, hair grows, and teeth change.
At two eight, kidney Qi flourishes, heavenly water arrives, essence Qi overflows and spills, Yin and Yang harmonize, hence a child can be conceived. At three eight, kidney Qi is balanced, tendons and bones are strong and firm, hence adult teeth grow to full length. At four eight, tendons and bones are sturdy, muscles are full and strong.
