It may have been the intention of the stone masons to remove these nubbins after the wall was completed.

Hark, a heavy step advancing,list, a father's angry cry, "He hain't shucked a single nubbin; where's that good-fer-nothin' Hi?" "Here, base catiff," comes the answer, "here am I who was your slave, But no more I'll do your shuckin', though I fill a bloody grave!