Thanks CD for his kind offer [of translation rights for Descent].

Feels it a duty to make CD’s "way of looking to fields [recte facts] under the guidance of ideas" known to his countrymen, especially since zoologists and physiologists seem to think science is nothing but the accumulation of facts and have almost forgotten to reason about them.

Explains that, contrary to Carl Vogt’s report to CD, he continues as Professor of Comparative Anatomy at Leipzig, but he has failed to get the place of the late Professor of Zoology, as he had hoped.

Answers some question about species.

Sends biographical sketch.

Now considers that a note on Nägeli would have to be too long to include. Discusses his differences with Nägeli. Cannot believe in spontaneous generation. At present the principle of life seems to him beyond the confines of science.