Wolves, varieties of, [90].
Woodpecker, habits of, [184].
——, green colour of, [197].
Woodward, Mr., on the duration of specific forms, [294].
——, on the continuous succession of genera, [316].
——, on the succession of types, [339].
World, species changing simultaneously throughout, [322].
Wrens, nest of, [243].
Y.
Youatt, Mr., on selection, [31].