Bonn
14 April 1875
Sir
By the same post I have the honour of sending you my last treatise.1 I have given in it a theory of life and how it was generated in the first beginning.
Yours very respectfully | E. F. W. Pflüger | Professor of physiology at the Bonn University.
Please cite as “DCP-LETT-9929,” in Ɛpsilon: The Charles Darwin Collection accessed on