Ellis speaks of Pliny at length in this chapter, and about the information we derive from him regarding the tradition of the Oak, the Oak Grove and mistletoe as a Druid Association. He points out that prior to the Alexandrian school, neither hide nor hair of a mention of an Oak Grove or mistletoe or Oak tree veneration exists, and yet, as soon as Pliny mentions it, everyone else jumps on board.

Another scholar Ellis quotes, Nora Chadwick, came up with some reasonable ideas regarding this sudden appearance, and it is simply thus: when the Romans attempted to suppress the Druids in Gaulish culture, and they could no longer teach, hold ritual, adjudicate or perform other functions openly, they retired to ‘off the beaten path’ places  – like forest groves – to continue to do what they could, to teach and practice out of the Roman eye.