Thanks for EK’s book [Werden und Vergehen (1876)].

Regrets he cannot write for EK’s journal, but his son, Francis, may do so.

Suggests EK as editor urge on readers [of Kosmos] the investigation of the causes of variability; why, for instance, do wild Pampas cattle change colour when domesticated? Thinks experiments and observations on recently domesticated animals and cultivated plants would throw light on the subject.