My dear friend, It was your particular request, before you went to the South Seas, that I should continue my researches into the formation and growth of <italic>Zoophytes</italic>, more particularly of those formerly called <italic>Ceratophytons</italic>, now <italic>Gorgoniæ</italic>; and known in English by the name of sea-fans, sea-feathers, and sea-whips, to which class the red coral should be added. This you thought the more necessary, as the accounts already published of them by the illustrious Dr. Linnæs and Dr. Pallas seemed to make them of a mixed nature in their growth, between animals and vegetables: a thing not easily to be reconciled to the usual operations of nature. I was so fortunate about that time to receive from my right honourable friend the earl of Hillsborough, a most excellent collection of different species of these animals preserved at the sea-side in spirits, by John Greg, esq. F.R.S. of Dominica. This hath enabled me to shew more clearly, that they are true animals, growing up in a branched form, and in no part vegetable.