On public grounds, and as an old fellow-labourer in the same rich field of philosophic inquiry, I avail myself of the opportunity afforded in publishing this brief outline of the primary divisions of the Animal Kingdom, to dedicate these pages to you in testimony of my admiration and approval of your late successful attempt to throw further light on that involved and obscure question, regarded by some inquiring minds as the mystery of mysteries of organic nature, the origin of species by natural law; or, as you have more happily and more definitely expressed the problem, “the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life.”

More than fifty years have now elapsed since the ‘Zoonomia’ of your illustrious ancestor, Dr. Erasmus Darwin, first opened my mind to some of “the laws of organic life,”² which he so clearly expounded, and so successfully applied to explain the abnormal phenomena of the human body; and nearly forty have already rapidly fled away since you and I were busied in exploring microscopically the delicate structures and the living phenomena of the lowest organisms abounding in the rich fauna of the Firth of Forth.³

But while I have been humbly occupied with the gleanings of our fellow-labourers in the cabinets and seminaries of Europe, and reporting the results to my youthful auditors,⁴ you have been widely surveying the grand domain of nature with a learned spirit over the oceans, seas, islands, and continents of the globe, in every latitude and in every clime, nearly from the one pole to the other, and accumulating that rich store of thought and observation which entitles you of all men to aspire to the complete solution of those great, though obscure problems of organic nature, which have so long perplexed philosophers; a labour which you have so successfully commenced, and in which you have already surpassed all your predecessors, from the time of Plato.

Intellectual triumphs like yours, which have been hailed with the assent and applause of all competent unbiassed minds at home and abroad, while they charm away the clouds of mysticism which overhang some parts of our science and of philosophy, and obscure the greatest truths of nature, alone add permanent glories to the annals of our country in the great struggle for intellectual preeminence and ascendency among the nations of the earth. With one fell sweep of the wand of truth, you have now scattered to the winds the pestilential vapours accumulated by “species-mongers” over every step of this ever-varying, ever-charming part of nature’s works; and your next movement will dispel the remaining clouds of “mystical supernatural typical intrusions” which still hang on the horizon of the sublime prospect, now opening to the view, of the natural animalization of the orbs of space by the same simple laws which govern the physical and chemical phenomena with such wondrous harmony throughout the rest of the material universe.⁵

I remain, my dear Sir, | With great respect and regard, | Yours most truly, | Robert E. Grant.

2 Euston Grove, Euston Square, London.

16th May, 1861.