EB is moving to Wiltshire for a week.

Tells CD of animals acquired, or about to be acquired, by the Zoological Garden.

Thanks CD for invitation to Down.

Wonders if George Darwin can explain why a thin stream of water poured from a jug always spirals right to left.

Discusses the top-knot turkey and the occasional appearance of the top-knot in a breed of cream-coloured turkeys.

Sexual differences in bird species and seasonal variation in plumage.

Gives CD a reference to one of his papers ["Remarks on the modes of variation of nearly affined species or races of birds", J. Asiat. Soc. Bengal 19 (1850): 221–9]

and discusses moulting in birds.

Quotes instance of an action by an elephant that apparently displays considerable intelligence.

Replies to CD’s questions on sexual differences in birds.

Describes his tour of the Netherlands. Reports on some of the specimens he saw on his trip.

Discusses the coloration of hair in aged monkey

and sexual differences in bird species.

Sexual differences in antelopes (Indian and African).

Will attempt to provide CD with the information requested as soon as he can.

Gives references to some recent papers and articles which might interest CD.

Is currently reviewing Wallace’s new book [Malay Archipelago].

Has found no difference between male and female rhesus monkeys at the Zoological Gardens in amount of facial hairiness. Observations on other monkeys.

Gives some observations and opinions on the appearance and behaviour of mandrills.

Notes on the interbreeding of different races of silkworm. [Forwarded with explanatory note by Edward Blyth.]

Asks for reference to EB’s article about tame deer on island in Aral Sea.

Asks to meet EB for a walk in the Zoological Gardens.

Is so unwell he must cancel appointment to meet at Zoological Gardens.

Many of EB’s remarks about Origin [4th ed. (1866)] are new to CD.

Thinks of writing a short essay on man.

Struck by EB’s remarks about orang. They are similar to Carl Vogt’s remarks on origin of man from distinct ape families.

Thinks similarity of orang to Malay must be accidental.

Will send Variation when it is published.

Has found EB’s MS most interesting and valuable. Fully half the facts were new to him; will probably use some.

Glad to hear about colours of Hylobates.

Cannot find any statement about which digits in man are most subject to syndactylism in Isidore Geoffroy [Saint-Hilaire]’s Histoire des anomalies [1832–7].

Asks questions concerned with seasonal and sexual changes in plumage of various bird species.

Does male woodpecker share in incubation?

Questions from CD related to bird plumage and sexual differences, with answers by EB.