As Stephen walks across the "damp crackling mast, razorshells, squeaking pebbles" in Proteus, an inexactly remembered line of Shakespeare's verse drifts into his mind: "that on the unnumbered pebbles beats." This detail from King Lear insinuates an association of "pebbles" with danger and death that recurs several times in the novel.

JH 2014

Pebbles below the cliffs of Dover. Source:

Gloucester atop the imagined cliff. Source: