Has received EH’s Die Radiolarien. Drawings admirably executed. Had no idea such low animals could develop such beautiful structures.

Thanks for paper ["Über die Entwicklungstheorie Darwins", Amtl. Ber. Versamml. Dtsch. Naturforsch. Aerzte 38 (1863): 17–30]. Delighted EH confirms his views. Many in England afraid to express views openly.

Thanks for praise [of Origin].

Comments on EH’s Die Radiolarien.

Grieved EH has suffered calamity [death of Anna Sethe Haeckel].

CD recovering from long illness.

Doing easy botanical work.

Mentions variability.

Discusses reception of CD’s views in Germany.

Can understand EH’s feelings on death of his wife.

CD was impressed by manner in which species in South America are replaced by closely allied ones, by affinity of species inhabiting islands near S. America, and by relation of living Edentata and Rodentia to extinct species. When he read Malthus On population, the idea of natural selection flashed on him.

Agrees with EH’s remarks on Kölliker ["Darwin’sche Schöpfungstheorie", Z. Wiss. Zool. 14 (1864): 174–86].

Asks EH to thank Carl Gegenbaur [for Vergleichende Anatomie der Wirbelthiere (1864)].

Sends Living Cirripedia [vol. 2].

Has employed translator for Fritz Müller’s book [Für Darwin (1864)].

Thanks for paper and speech.