The Mystic Perfections achieved by actually successful yogis are 8 in number anima siddhi refers to the power by which one can become so small that he can enter into a stone modern scientific experiments enable us to enter into stone because they provide for Excavating so many Subways penetrating the hills Etc so anima siddhi the Mystic Perfection of trying to enter into stone has also been achieved by Material Science similarly all of the yoga siddhis or Perfections