Frank Sidgwick, The Sources and Analogues of 'A Midsummer-Night's Dream'… (1908)
“ Shakespeare had to introduce into his play the magic herb which was to alter the loves of those into whose eyes it was squeezed. We may reasonably guess that he had read somewhere one of the many popular legends that explain why the violet is purple, why the rose is red, etc.; there are some in Ovid's Metamorphoses [1] which Shakespeare read in Golding's translation. He saw an opportunity of paying a graceful compliment to Elizabeth by saying that the magic flower, once white, had been empurpled by a shaft of Cupid's drawn at the fair vestal and imperial votaress, who yet passed on untouched ”
