The Seven Ages.

The lives of three Wattles, the life of a hound.
The lives of three Hounds the life of a Steed.
The lives of three Steeds the life of a Man.
The lives of three Men, the life of an Eagle.
The lives of three Eagles the life of a Yew.
The lives of three Yews, The length of of an Age,
Seven Ages from Creation to doom.