Thanks CD for Expression.

Suggests saving some anthropoid Quadrumana from extinction by taming and studying them in their own environments to learn about their development.

Sends "squib" he has written exposing the folly of some of Louis Agassiz’s ideas. AG cannot "fire off [his] cracker" in U. S. so sends it to amuse CD. If it is sent to Nature, CD must not give AG’s name. [See "Survival of the fittest", Nature 7 (1873): 404].

Additional errata in Descent.

Sends a paper on behaviour he has observed in ants.

Winter in Duluth.

HAH is leaning toward spiritualism.

Limit of natural and sexual selection.

Has been around the world three times.

CD answers a question about the attitude of foreign naturalists towards Darwinism by distinguishing between the belief in evolution and belief in natural selection. Gives the views of [Louis] Agassiz, [R. A.] Kölliker, [C. W.] Nägeli, [Ernst] Häckel, [C. F. W.] Claus, [F. J.] Cohn, Alphonse de Candolle, [J. L.] Claparède, Asa Gray, Gaston de Saporta, [E. D.] Cope, and [Carl] Gegenbaur.

Sends his book [Die Befruchtung der Blumen (1873)]. Hopes CD will publish an opinion of it.

Hopes JC-B thinks that CD has properly acknowledged his debt in Expression.

Gives a case of peculiar behaviour in cats that apparently is inherited.

Remarks on the "grief-muscles" shown in a Dürer picture.