Urges AG to generalise from his observations on the flora of the northern U. S.

Expected to find separation of sexes in trees because he believes all living beings require an occasional cross, and none is perpetually self-fertilising. The multitude of flowers of a tree would be an obstacle to cross-fertilisation unless the sexes tended to be separate.

The Leguminosae are CD’s greatest opposers; he cannot find that garden varieties ever cross. Could AG inquire of intelligent nurserymen on the subject?

Thanks AG for information on protean genera; much wants to know whether their great variability is due to their conditions of existence or is innate in them at all times and places.

No summary available.

Would rather not serve on Royal Society committee [for a North American exploring expedition]. Suggests subjects for geological investigation.

Ranges of species in large vs small genera: Asa Gray’s compilation fits CD’s expectation.

CD studies seedling mortality in his weed garden.

JDH’s work on Indian flora.

Sends account of his successful experiments in feeding wheat seeds to minnows.

Reports on wheat in the stomach of fish he caught.

Asks whether Crustacea from temperate parts of the Southern Hemisphere are more strongly analogous to those in same latitudes of the Northern Hemisphere than are Arctic to Antarctic Crustacea.

Discusses astonishing finds of mammalian and reptilian remains in Purbeck beds; notes reactions of Lyell.

Has doubts about Richard Owen’s recent classification of mammals [J. Proc. Linn. Soc. Lond. (Zool.) 2 (1858): 1–37].

Works away [on Natural selection].

Asa Gray has given valuable assistance.

Independence of variation from climate shown by several plant genera; CD asks for confirmation.

Progressing with book [Natural selection].

Recommendations of books of general interest [for the Royal Society library]. These include [Louis] Agassiz’s works, [William] McGillivray’s [History of] British birds, and David Low’s [On the domesticated animals of the British Islands].

Comments on current candidates for the Royal Society.

JDH cites W. H. Harvey’s observations on Fucus and David Don’s on Juncus as examples of variations that are independent of climate. There are many such cases. Gives his working scheme for categorising variation.

Thanks JDH for response on variation. Studying variations that seem correlated with environment, e.g., north vs south, ascending mountains.

CD’s weed garden: observations on slugs killing seedlings.

Seed-salting. One-seventh of the plants of any country could be transported 924 miles by sea and would germinate.

Lists groups of insects absent from the Madeiran fauna.

CD returns a letter from Wollaston.

Although opposed to the Forbesian doctrine [of continental extension] as a general rule, CD would have no objection to its being proved in some cases. Does not think Wollaston has proved it; nor can anyone until more is known about the means of distribution of insects – but the identity of the two faunas is certainly interesting.

His health is very poor and his "everlasting species-Book" quite overwhelms him with work. It is beyond his powers, but he hopes to live to finish it.

Has found no reference to construction of bees’ cells in works referred to by CD. Describes cell of Osmia atricapilla. Hive-bees’ cell was described at Entomological Society.

Thanks for pigeon.

Are there Shetland birds chequered with black marks, as Carl Julian Graba states are in Faeroes [Reise nach Färö (1830)] and Col. King in the Hebrides?

Fish will take both sorts of seeds sent by CD, but will not take oats.

In reply to CD’s query [see 2072], JDD describes what little is known about the crustacea of the Antarctic and southern lands.

Knows of no species of the cold temperate south identical with those of the cold temperate north.

Asks PHG to conduct an experiment to see if young littoral molluscs will cling to a duck’s foot – CD seeks to explain distribution of molluscs without adopting E. Forbes’s [continental extension] theory.

Curative power of hydropathy.

General hairiness of alpine plants questioned: direct environmental effect.

CD has long felt JDH is too hard on bad observers.

His impressions of the hydropathic establishment and E. W. Lane. Is convinced the only thing for "chronic cases" is the water-cure.

Asks if WDF knows of any breed of pig that originated or was modified by a cross with a Chinese or Neapolitan pig, and whether the crossbreed bred true.