Describes his research on cirripedes. Asks to borrow specimens. Comments on previous work on the subject.

Send thanks for informing him of barnacles and asks that they be sent, directed to him, to the Geological Society.

CD makes progress with barnacles. Describes "supplemental" males in detail. In working out metamorphosis, their crustacean homologies followed automatically.

CD opposes appending first describer’s name to specific name.

Thanks for note and enclosure. Has written to [David?] Landsborough to say dried specimen was just what he wanted. Would like some more in spirits.

Very unwell.

Thanks LA and sends thanks to A. A. Gould for specimens. Describes principal findings of his research on cirripedes. Is obliged for information Joseph Leidy gave about cirripede eyes. Describes anatomical features and chief aspects of growth. Describes discovery of parasitic males and a species parasitic upon other cirripedes.

Obliged for drawings and coins. Cannot tell what the stone is.

Discusses his account. Mentions death of his father and his own inheritance.

Thanks JWL for the use of a schoolroom.

Arranges to meet JWL’s son [John] to discuss use of microscope.

Mentions illness.

Thanks JWL for his paper ["Shooting stars", London Edinburgh & Dublin Philos. Mag. 32 (1848): 81–8, 170–2; 35 (1849): 356–7].

Has altered and added to HES’s list [compiled for Bibliographia zoologiæ et geologiæ, edited by Louis Agassiz and enlarged by HES, (1848–54)].

On zoological nomenclature CD cites a case in which he believes more harm than good would be done by following the rule of priority. Thinks the rule of the first describer’s name being attached in perpetuity to a species has been the greatest curse to natural history. Every genus of cirripedes has a half-dozen names and not one careful description.

Sends a paper he once wrote [missing] on the subject [of zoological nomenclature].

Asks for account on South America and sales of Coral reefs and Volcanic islands.

Thanks WJH for information on J. D. Hooker’s progress.

J. D. Hooker promised a copy of his Galapagos paper. Can WJH forward one to the Athenaeum?

HES’s arguments are of great weight, but CD cannot yet bring himself to reject well-known names for obscure ones. Sends four cases that he thinks will stagger HES. Cites his problems in classifying cirripedes. CD cannot bear to give new names, yet may do wrong to attach old ones. Not one species is correctly defined. The harm done by "species mongers".

His memory of his recently deceased father is a treasure to him.

Thanks WDF for information on the water-cure. Dislikes the thought of it.

Reports results of his experiments with tied-up fruit-trees.

Happy to support LAR’s application to the Royal Society.

Requests JPM’s assistance by lending or giving him cirripede specimens. The anatomy of cirripedes has been most imperfectly done, and their classification is a perfect chaos.

HES’s letter will fructify to some extent: CD will try to be more faithful to rigid virtue and priority. Would not adopt his own notion in cirripede book without prior approval by others. Will not append "Darwin" to any of his species. Feels sure many others share his aversion.

Asks HES’s opinion on retention of generic name Conchoderma.

Thanks HES for solving his problem. Has some difficulty with HES’s type-species. In arranging genera in a natural order it is often impossible to say which species should be considered the type.

Thanks RO for his note on Conchoderma hunteri [see Living Cirripedia 1: 153].

Has been very unwell; has lost four-fifths of his time. Will go to Malvern to try the water-cure for his vomiting, which regular doctors cannot cure.

Has done some pretty homological work with cirripedes.

Thanks him for cirripede specimens.

Sends detailed report on the prospects for a settlement on the coast of Patagonia, pointing out many problems, and recommending instead the Falkland Islands.