Moritz Wagner is going to attack selection theory in his new book on his travels in America [Naturwissenschaftliche Reisen im tropischen Amerika (1870)].

K. G. Semper may attack CD’s theory of coral islands.

Describes his brother Alexander’s discovery of male of Bonellia, a striking example of dimorphism. Encloses a plate with notes on his brother’s work.

The difficulty his wife, Sofya Kovalevsky, has had as a woman in being admitted to Berlin University. Kirchow [Gustav Robert Kirchhoff], at Heidelberg, has taken an interest in her.