Polarity
in physics, the disposition in a body, or an elementary molecule, to place its mathematical axis in a particular direction. Also, the disposition in a body to exhibit opposite or contrasted properties or powers in opposite or contrasted directions, specifically the existence of two points, called poles , possessing contrary tendencies. Examples , attraction and repulsion at the opposite ends of a magnet, opposite tendencies in Polarized light, etc. In biology Prof.
Edward Forbes, considering that the relation between the palæozoic and neozoic life assemblages is one of development in opposite directions, called it polarity POLARIZATION