Dear Sir

I write You with a peculiar request and should be very gratified for Your granting it. The whole winter I was occupied by a memoir on the Anthracotheriums, of which I found in different collections a large quantity, so that many species may be completely restored and their bony frame completely investigated.¹ But, besides, at the request of some palaeontological friends, especially Prof. Rutimeyer, I tried to make a general review of all the extinct Ungulates and propose a natural classification for them.²

Little by little as my materials grew more abundant the sketch enlarged until it reached now considerable dimensions, the result beeing a very clear account of the developement of the whole Ungulata from the oldest Eocene to the recent period. There is little circumlocution, but a large body of dry positive facts, and these prove most undoubtedly the gradual evolution of all the recent forms from a limited number of Eocene and miocene types. I am actually printing the memoir in the “Palaeontographica”, but as it contains about twenty sheets, it will not be out before ten or twelve weeks.³ Will You allow me dear Sir to dedicate it to You; as it is the first positive attempt in this direction, founded on a large body of evidence derived from the whole skeleton I will be very happy if the dedication will be made to You as the founder of the Evolution-theory.—⁴

My paper in the Royal got through the Ordeal of the comittee and is ordered to be printed, so that my German memoir and the paper in the Ph. Trans. will appear at once.⁵

As good news I may communicate to You that my brother is gone to la Calle, near the Tunisian frontier and made there the complete development of two Brachiopoda, the Argiope and Thecidium.⁶ The Argiope has a free swimming larva very alike the Sagitta with a bipartite mantle and a slender tail; after some time the larva attaches itself by this tail to some surface and turns her mantle over the head; the tail grow now to a peduncle and both halves of the upturned mantle begin to secrete the shell. The development of internal organs is also completely worked out. Thecidium is much more complex.— There are some faint hopes that the Crania will lay eggs too, but it is not quite sure.

When I left England Your health was far from being well, I hope You had a better winter and are going well now.⁷ More than one thousand copies of Your book is sold in Russia, as soon as the cost of printing will be covered my brother will be most happy to send in Your schare in the Edition.—⁸

Please remember me to M^rs. Darwin and the ladies.—

Your very truly | W. Kowalevsky

P.S. You have certainly read the account of Marsh about the cretaceous bird with teeth in both jaws and fish vertebrae.⁹ And the Dinoceras! really one is happy to be a Palaeontologist in the Vertebrates.¹⁰