The snake. Among the Romans the snake was the conventional representation of the genius loci.
figures of serpents were often painted against a wall, as the cross is in modern Italy, and
answered the purpose of our sign “Commit no nuisance” (Pers. i.113
). As the emblem of Aesculapius
(q.v.), the snake was the sign that hung before the Roman pharmacies,
answering to our pestle and mortar. It was also the military ensign of a cohort, being then
commonly termed draco.