Crossword-Solution: MUTATORY 8 letters, 1 clue 🏆 scrabble score: 13

DeVries discourages the notion that mutations are always occurring everywhere, which might seem to be one of the inferences from his theory, and his twenty-fourth lecture of the series, delivered before the University of California is entitled “The Hypothesis of Periodic Mutations.” The common primrose, he says, seems to be immutable at present, and argues that it must have had a mutatory period sometime in the past, when, perhaps, the evening primrose was not mutating.