His trip across the Andes and back was his most successful excursion: can clearly demonstate that the western part of the double line of mountains is much older, with fossil shells at 12000ft; the eastern line may be as modern as the Patagonian plains. If proved, this is an important fact in the theory of the formation of the world. Has found petrified trees.

Living quietly on the ship and eating good food has been good for him. He longs for home. Peru is in a miserable state.

Some of CD’s letters were read at Geological Society in London. Professor Sedgwick says of CD, "doing admirably … collection above all praise … will have a great name among the Naturalists of Europe".

Erasmus has taken office of Clerk to a Government Commissioner. Other family news.

CD’s impressions of Sydney and of FitzRoy’s character and temperament.

CD’s 27th birthday. News of family and friends. A niece, Mary Susan Parker, born 31 January.

Beagle is again in Brazil because of need to check on "singular disagreements in the Longitudes".

Pleased by Sedgwick’s praise.

Father says he sowed broom plants soon after house was built in 1798; these never came up. In 1835 the terrace was made; thereafter the broom sprang up.

Advice on a medicine CD is taking.

FitzRoy is hard at work on his book [Narrative, vol. 2].

CD’s health is improved.

Describes his visit to zoo.

Gives news of E. A. Darwin and Harriet Martineau.

Thanks for ham and corrections in spelling. Gives account of his social activities in past week.

Recounts dinner at Erasmus’ house with Harriet Martineau and others, and a visit to Cambridge to stay with Henslow and meet old friends again.

Gives some information on Darwin family history.