His trip to the interior was full of interest, but exhausting physically. Expects to stay at least a fortnight at Botofogo, because the Beagle returns to Bahia to correct a difference in the longitude measurements. Writes of his companions, of FitzRoy, and of his journal – which he has sent home.

Writes of voyage and his work in natural history: geology, collecting insects (freshwater beetles and spiders at Botofogo Bay); life at sea, sublime views ashore.

Lists letters received and those sent; comments on family happenings.

The Beagle is back [from Bahia]; two sailors and "little [Charles] Musters" died of fever. In 14 days they sail for Montevideo, then to Rio Negro, then on to where no man is known to have been before.

His first letter to JSH since December. Recounts his seasickness, geologising and marine collecting at St Jago [Santiago, Cape Verde Is.]; his first tropical forest. Collecting small insects from the tropics. His Welsh trip with Sedgwick has been extremely valuable.

Summarises experiences since leaving England. "How intimately what may be called the ""moral part"" is connected with the enjoyment of scenery." The loneliness of the voyage.

Sailing next day to Montevideo. He has taken many hitherto undescribed animals. Describes the glories of the Brazilian forest.

Mentions his concern over the Reform Bill.

Regrets leaving the tropics, despite interest in a land where Europeans have never been. They have experienced political turmoil at Montevideo. Natural history going well.

Specimens being sent off. Describes his collection of rocks, plants, and insects. Some particularly interesting specimens.

Brief summary of the voyage so far. His delight in the Brazilian forest; his trip into the interior; the turbulence at Rio; has grown a beard.

During the past two months CD has been lucky with fossil bones, and he is also finding new specimens of living animals.

He describes an ostrich hunt.

Has received several letters from home.

He enjoys Buenos Aires and admires the señoritas. Tierra del Fuego is next.

Sketches the Beagle’s travels – Rio de Janeiro, Montevideo, cruise to the south and return – and what the future holds. Writes with nostalgia of England and says he sees no end to the voyage.

He enjoys and has been lucky principally in geology and among pelagic animals; has found remains of large extinct animals.

A French collector [Alcide d’Orbigny] has been at the Rio Negro and will probably have "taken the cream". CD’s luck with fossil bones, among them a large extinct armadillo-like animal. Describes some birds, toads, Crustacea, and other marine specimens. Nearly all plants flowering at Bahia Blanca were collected. Is sending two large casks of fossil bones by packet.

Account of the four-month voyage to Tierra del Fuego, Cape Horn, and return. The Fuegians are landed with Richard Matthews [the missionary in charge of them]. Storms, seasickness, hostile savages, and scenery are described. His increasing interest in all branches of natural history makes the hardships worth while. FitzRoy buys a schooner. CD will stay at Rio Negro while it is fitted.

Description of the months at Tierra del Fuego. His first sight of the primitive Fuegians. Geological and zoological observations and specimens.

The Falklands: geological and zoological observations.

Convinced the [Megatherium] sent to Royal College of Physicians [by Woodbine Parish] belongs to same formation as bones he sent home.

Longs to be on the other side of the Horn; tired of these countries. Natural history makes him continue. He now knows it will remain his favourite pursuit for the rest of his life.

Comments on slavery.

Will have additional space on board and a servant [Syms Covington] who will help him with the collection of birds and quadrupeds.

Asks for books, a lens, and four pairs of shoes.

He misses society. "I often conjecture what will become of me; my wishes certainly would make me a country clergyman. – You expect sadly more than I shall ever do in Nat. Hist: I am only a sort of Jackall, a lions provider; but I wish I was sure there were lions enough."

Has collected a host of minute beetles, some reptiles, small quadrupeds, and fishes. Invertebrate marine animals are his delight. The pleasure of working with microscope ranks second only to geology.

Describes Tierra del Fuego and Cape Horn; was reminded of hours at Barmouth; chafes at the length of the trip.

Hopes the Whigs will do away with slavery – has seen enough of it and Negroes to be disgusted with the lies heard in England.

Fears JSH will think his collections scanty. Makes it a constant rule to prefer obscure and diminutive tribes of animals.

Now has a servant whom he has taught to skin birds, etc.

Lists four barrels of specimens he is sending.

Gives future route. He looks forward to the western coast of South America.

With the help of General Rosas, CD has just finished an overland journey from Patagones to Buenos Aires; he tells of fossil finds at Bahia Blanca and Guardia del Monte. Spring reminds him of home.

Informs JSH that a Spanish friend has offered him a cargo of bones. If they arrive, he has arranged with Edward Lumb to forward them to JSH. [Forwarded to JSH with 244.]