In their files, they maintained graphs that indicated when each female was at the peak of her fertility cycle.

A feature of the fertility cycle of horses and other large herd animals is that it is usually affected by the seasons.

They've adjusted their fertility cycle to the salmon runs.

As abstract as these dances seemed, many were obviously designed to make the crops grow or, in their courtship games, related to fertility cycles.

Some anthropologists have questioned the energy cost of rebuilding the endometrium every fertility cycle.

Both Christ and the fertility cycle seem terrifying.

Yet under all the various forms, the sexual act and natural fertility cycles persist.

In his perception of the horror of fertility cycle and sexuality, Eliot saw himself as following Baudelaire.

The Rock opens with the seasonal fertility cycle which had horrified the trapped Eliot of the earlier poetry and the dramatic fragments.