Sends Ernst Haeckel’s [Generelle] Morphologie [1866] and C. K. Sprengel’s book [Entdeckte Geheimniss der Natur (1793)].

A. Gaudry and L. Rütimeyer have declared in favour of CD’s views.

No summary available.

Criticism of ARW for too little esteem of the role of sexual selection as agent in giving colour.

Response to other topics.

Cannot judge GWC’s fitness for the Botanical Chair at Oxford. But CD appreciates his work, particularly that on spontaneous generation [Proc. R. Soc. Lond. 13 (1863–4): 313; 14 (1865): 178].

Encloses a testimonial for GWC [see 6162]. Feels himself poorly qualified to give a testimonial for a botanist and apologises for his brevity.

Asks about the ratio of male to female Lepidoptera.

Thanks JJW for his great assistance.

Discusses sexual selection in birds.

Sends queries on secondary sexual characteristics of birds.

Has often marvelled at the different growth of the flowering and creeping branches of ivy.

AG’s review of Variation [Nation 6 (1868): 234–6] very good.

CD’s fondness for Pangenesis; although an "infant cherished by few", CD expects it to have a long life.

Sends some questions on secondary sexual differences of fishes [missing], which he hopes AG will look over.

Invites AG to come to Down.

Encloses queries on sexual differences and nest-building habits of fish.

Returns volumes of the Ibis.

Requests T. C. Jerdon’s Birds of India

and Thomas Bell’s British reptiles

as well as vols. 5 & 6 of Ibis.

WDF’s letter gives CD the kind of facts he wants. His story about peacocks is so good that CD will quote it [Descent 2: 46].

Pleased WDF approves of his book [Variation]

– "beloved Pangenesis disagrees badly with many".

Thanks for answer to questions.

Has analogous questions on reptiles that he will send to AG. The subject interests him, but CD must try not to fall into his common error of "being too speculative".

Questions on marmosets and the vocal organs of Hylobates.

CD cannot remember whether correspondent believed the wing that Gallus bankiva opens and scrapes before the female, is ornamented. He fears it is not.

Thanks THF for correcting the error in Orchids.

Asks him to find out what insects visit the fly orchid and for what purpose.

GHKT should not take more trouble about human expression. Discusses contraction of orbicular muscles in elephants.

Asks about colour of first plumage of breeds of Ceylon fowls in which hens alone are coloured.

Encloses grass from locust dung sent from Natal. Asks for name of grass.

Thanks for information on sex ratios of Lepidoptera.

Agrees that entomologists have best means of proving derivation of species.

Inquires about the colour of first plumage of poultry breeds and development of distinguishing features.

Lists specimens he wants from Mr Janson, emphasising that he always wants male and female.

He extends an invitation for a Sunday in early June.