. "x' has a value equal to the valence of Me; and (e) said reducing halide source is represented by the formula Al(R3)3-m Xm wherein each R3 is independently hydrogen or a hydrocarbyl group having from 1 to about 20 carbon atoms, X is a halogen atom and m has a value from 1 to 2;thereby producing a polymer having a relatively small average particle size of not greater than 200 microns and a relativel" . . . . . .