The clichés were obtained and Meldola’s translation published in the Proceedings of the Entomological Society for 1879, p. 20. The new contribution to the theory of mimicry was at first somewhat severely criticised, even Bates being adverse to it. Subsequent work has abundantly justified it as by far the most important addition to the subject since Bates’s original paper. In fact, many cases which have been up to the present explained under the theory of true (Batesian) mimicry are now believed to come under that which we owe to F. Müller--viz. convergence between specially protected forms for mutual benefit. An interesting paper by Dr. F. A. Dixey, published in the Transactions of the Entomological Society for the present year (1896), contains convincing arguments in favour of this view as regards some of the _Pieridæ_ of South America in relation to the _Heliconidæ_ and _Papilionidæ_ which they resemble. It is of the highest interest to learn that the first introduction of this new and most suggestive hypothesis into this country was due to the direct influence of Darwin himself, who brought it before the notice of the one man who was likely to appreciate it at its true value and to find the means for its presentation to English naturalists. In the next year Meldola wished to translate further papers of Fritz Müller’s, and received the following letter on the subject:-- “_Nov. 25/80._ “Down. “MY DEAR SIR,--I can well believe that your labour must have been great, and everyone is bound to aid you in any way. “No. I. of F. Müller’s paper is in the August no. for 1877. “No. II.--is in the October no. for 1877. “Both these articles I remember thinking excellent. “I am not one of the editors of Kosmos, only a kind of patron(!) and therefore cannot give permission; but when you write to the editors you can say that I have expressed a hope that permission would be granted, you acknowledging source of papers. “Heartily wishing you success and in haste to catch first post, I remain yours very faithfully, “CH. DARWIN.” Shortly after the date of the last letter Professor Meldola came across a copy of Thomson’s “Annals of Philosophy” on a bookstall. It bore the name “Erasmus Darwin” on the first page, and Meldola offered it to Charles Darwin, thinking it might have belonged to his grandfather. “_March 12th, 1881_ [The date was evidently May, and not March]. “Down.