Summary

Asks for CD’s "Sketch of an infant" [Collected papers 2: 191–200]. He has made observations on new-born children and mammals to determine what behaviour is inherited and what acquired.

Summary

Sends his book [Naturwissenschaftliche Thatsachen und Probleme. Populäre Vorträge (1880)].

Anxious to receive Movement in plants because CD’s methods may be applicable to his experiments on the earliest movements of animal embryos.

Summary

CD’s comment that certain instincts originate as variations of the brain, rather than as habits, is supported by Brown-Séquard’s and C. F. O. Westphal’s work on epileptiform movements.

Summary

Has given a lecture series on Darwinism which was attended by 200–500 students.

Would like to compile a list of CD’s works.

Summary

Notes the differences in haemoglobin between species; this proves, to WP, that natural selection does not act only on morphological development.

Remarks on the differences and similarities in the effects of prussic acid on different groups of animals.

Questions CD on his early education and influences.

Summary

Sends his "Charles Darwin, eine biographische Skizze" [Das Ausland 2 Apr 1870].

Summary

Thanks CD for Origin, 5th ed.

Comments on reviews of Descent by the Duke of Argyll and A. R. Wallace.

Lists the Darwinian professors at Jena.

WP’s work shows external ear to have no physiological functions.

W. Müller’s book not yet arrived. Will send Müller’s next works.

Summary

Delighted that CD does not hesitate to follow his theory to its last consequences. "This is far more difficult in England than in Germany."

Wilhelm Müller in his new book [Beiträge zur pathologischen Anatomie und Physiologie des menschlichen Rückenmarks (1871)], adduces many facts in favour of CD’s theory.

Various observations on the human ear. [See Descent, 2d ed., p. 14 n.]