Sends some examples of Gentiana that he thinks may shed light on the origin of double flowers. Since specimens grew in sterile soil their double flowering cannot be attributed to excess food. CD advances the hypothesis that some change in natural conditions causes sterility, which then causes compensatory development of petals, the organs closest in morphology to those whose functions have been checked.

Discusses classification of animals. Degree of affinity different for different taxonomic groups. Discusses affinity of Ornithorhynchus or Echidna to reptiles.

Brain of whale is highly developed; on differences among brains of Quadrumana.

Calls CD’s attention to an article about William Herbert’s hybrid Narcissus.

Declines invitation to ride because he is "so very subject to headache".

Explains what he means when he attempts a "natural classification", defining his words and using man as a standard; gives examples. Classification of Aptera and Diptera.

Discusses his discharge from the Zoological Society. Is to see Robert Brown about the British Museum position.

CD sends off his notes [corrections and additions to his Journal of researches] which he hopes ED will introduce [in German translation].