California Code, Probate Code - PROB § 6209

Whenever a distribution under a California statutory will is to be made to a person's descendants, the property shall be divided into as many equal shares as there are then living descendants of the nearest degree of living descendants and deceased descendants of that same degree who leave descendants then living;  and each living descendant of the nearest degree shall receive one share and the share of each deceased descendant of that same degree shall be divided among his or her descendants in the same manner.