The female sepia goes pregnant in the spring-time, and lays
its eggs after fifteen days of gestation; after the eggs are laid
there comes in another fifteen days something like a bunch of
grapes, and at the bursting of these the young sepiae issue forth. But
if, when the young ones are fully formed, you sever the outer covering
a moment too soon, the young creatures eject excrement, and their
colour changes from white to red in their alarm.

Crustaceans, then, hatch their eggs by brooding over them as
they carry them about beneath their bodies; but the octopus, the
sepia, and the like hatch their eggs without stirring from the spot
where they may have laid them, and this statement is particularly
applicable to the sepia; in fact, the nest of the female sepia is
often seen exposed to view close in to shore. The female octopus at
times sits brooding over her eggs, and at other times squats in
front of her hole, stretching out her tentacles on guard.