Toe, extra toe in poultry, [76]

Tschermak, E., [29]

Unit-character, definition of, [31]

Variation, [14], [137], [139]

Walnut comb, [33]

Weismann, A., [13]

Wheat, beard in, [74]

experiments with, [157]

White, dominant in poultry, [72]

Wilson, J., [168]