caducity

Magpies, crows, and jays, evince symptoms of caducity at the same age.

Pensive musings upon the caducity of the human race are, generally, rather feminine than masculine.

The "caducity" and "persistency" of floral envelopes furnish some valuable characteristics for the distinction of species.

Let us deduct even from old age the years of infancy, the years of caducity, and the years of sleep,—alas!