Returns letter mailed by mistake [see 4361].

Hopes CD will accept gift of his Radiolarien [Die Radiolarien, 2 vols. (1862)].

No book has made such a powerful impression on EH as the Origin. Most older German scholars opposed to it, but number of supporters growing among the young. Fortunately strength of religious dogmas now small among educated Germans. Situation in Jena especially favourable. Defended CD’s theory last year at Congress of German Scientists in Stettin.

Intends special study of jellyfish.

Plans general work on natural history.

Hard fate [death of Anna Sethe Haeckel] has made EH indifferent to criticism.

Colleagues August Schleicher and Carl Gegenbaur also convinced by CD’s theory.

Sends photographs of himself and his late wife [Anna Sethe]. Describes death of his wife.

Plans trip to the Alps.

Thanks CD for biographical information about himself.

Mentions Goethe as early evolutionist.

Cites Kant as early supporter of epigenesis.

Mentions criticism of CD’s theory by R. A. von Kölliker ["Über die Darwin’sche Schöpfungstheorie", Z. Wiss. Zool. 14 (1864): 174–86].

Thanks CD for notes concerning the development of his ideas about the origin of species. Says August Schleicher and Carl Gegenbaur also interested.

Names new supporters of CD’s theory, including Max Schultze, Rudolf Leuckart, and Alexander Braun. Zoologists have been more interested than botanists.

He is writing a general work on the relationships among animals [Generelle Morphologie der Organismen (1866)].

Comments on Fritz Müller’s Für Darwin [1864].

Gegenbaur is revising his Grundzüge der vergleichenden Anatomie [2d ed. (1870)] to accord with evolution.

Thanks CD for copy of book on balanids [Living Cirripedia, vol. 2].

Has heard from Huxley that CD has been ill.

Progress on his book [Generelle Morphologie (1866)] has been slow.

Has been named "ordentlicher Professor". Has 150 listeners in his lectures on CD’s theory.

Thanks CD for copy [of "Climbing plants"].

Sends his book [Beiträge zur Naturgeschichte der Hydromedusen, 1. Heft: Die Familie der Rüsselquallen (Geryonidae) (1865)] and two articles.

Calls attention to a new rhizopod from Nice.

Comments on CD’s health.

Discusses origin of life and differentiation of principal classes of plants and animals.

Discusses Generelle Morphologie and its chapter on embryological development.

His lectures on CD’s theory.

Asks CD for larger portrait of himself and for several copies of the small photograph. Will send photographs of German scientists in exchange.

Discusses exchange of photographs with German scientists.

Comments on attitudes of German scientists toward CD’s theory.

Names several scientists who exchanged photographs: Braun, Virchow, Leydig, and Dohrn.

Will visit CD on Sunday, 21 October.

Will spend winter in research on Madeira and Tenerife.

CD will soon receive copy of Generelle Morphologie.

Thanks CD for new edition of Origin [4th ed. (1866)].

Comments on CD’s criticism of the harsh tone of Generelle Morphologie. Thinks he may have harmed himself but not the cause. Believes a radical reform of the science necessary, and since most scientists take a prejudiced view of the matter, a vigorous attack is essential.

Describes his travels in Canaries, Spain, and France.

Is engaged to marry Agnes Huschke. Will make wedding trip to Switzerland and Italy in autumn; therefore cannot visit CD as hoped.

Discusses present research. Comments on Protoamoeba with respect to origin of life. Says it makes question of common or separate origin of phyla unimportant.

CD to receive honorary diploma from Imperial Zoological Botanical Society in Vienna.

Sends photograph of Viennese botanist, August Kanitz.

Describes his lectures on CD’s theory.

Thanks CD for copy of Variation. Comments on book.

Describes work of two protégés in Jena: Nicolas von Miklucho[-Maclay] and Anton Dohrn.

His cousin, Wilhelm Bleek, is sending an article about the origin of language.

Asks to keep book a few months longer but will return it if CD needs it [Webb and Berthelot, Histoire naturelle des Îles Canaries, vol. 3, pt 1: Géographie botanique (1840)].

Describes research on Siphonophora.

Describes life in Jena. Mentions alpine accident during wedding trip.

Has received English edition of Variation. First volume of German edition came three months ago. Comments on book.

Will send copy of recent lectures on human evolution [Entstehung des Menschengeschlechts (1868)]. Gegenbaur much interested in the subject.

Considers Selachius the ancestral form of the fish and hence of all higher vertebrates. Believes their swim-bladder became lung of amphibians.

Mentions cases of hybrid crosses between rabbits and hares producing fertile offspring.

Thanks CD for article by G. H. Lewes ["Mr Darwin’s hypotheses, pt 1", Fortn. Rev. n.s. 3 (1868): 353–73]. Comments on article.

Describes hybridisation experiment carried out on rabbits and hares by Dr Conrad.

Encloses description of Monera

and a phylogenetic table of vertebrates.

Mentions work on Medusae.

The controversy over CD in Germany.

Comments on CD’s health.

Has received gold medal from Dutch Academy of Science for Zur Entwicklungsgeschichte der Siphonophoren [1869].

His Entstehung des Menschengeschlechts [1868] has been sharply attacked by the clergy.

Thanks CD for comments [on Entstehung des Menschengeschlechts].

Comments on Goethe and Kant as early evolutionists.

Describes birth of his son. Mentions child’s "atavisms".

Comments on experience of being a father.

Discusses possible English edition of Generelle Morphologie. Mentions necessary revisions.

Thanks CD for comment on Natürliche Schöpfungsgeschichte.

Discusses problem of assigning specific times to origin of classes.

Comments on 5th edition of the Origin [1869];

preparation of second edition of Natürliche Schöpfungsgeschichte [1870].

The reception of CD’s theory. Mentions support of Pieter Harting and Michael Sars.

EH’s research on calcareous sponges and plans to publish monograph on them.

Thanks CD for assistance concerning sponge specimens. Mentions Englishmen who have sent specimens. J. S. Bowerbank has not answered requests.

Sends articles dealing with sponges and Medusae. Cites passages for CD to read. Suggests passages from Entwicklungsgeschichte der Siphonophoren [1869].

Describes meeting with Sars and his trip to Norway.

Discusses applicability of evolutionary theory to the question of human origins.

Describes revisions in 2d edition of Natürliche Schöpfungsgeschichte.

His research on calcareous sponges.

Mentions evolutionary content in Gegenbaur’s Vergleichende Anatomie [2d ed. (1870)].

Received copy of Descent.

Discusses CD’s comments on EH’s work.

Speculates about reception by press and scientists.

Remarks on sexual selection;

on human relationship to catarrhine apes.

Has rejected offer of chair at Vienna.

Compares Jena to Down.

Describes growth of his salary.

Mentions birth of Emma Haeckel.

A. M. Norman’s collection of calcareous sponges is very valuable.