Geno depignentation, normal brown color; UOehair faintly grey} “O-~ hair grey; 3C~hair greyiah-whito; 10+ hate yolte. “The figuiwe given in the table represent saverngs velues caloulated from cbeerwations of 10 to 30 mice at each station, except 7 k for which only 1 meuso is available. Approxinately 5 controls were examined on each date given. noe ARGHIVER