Discusses the ranges of alpine species in U. S. and considers the possible migration routes of such species from Europe.

Lists those U. S. genera which he considers protean and describes the U. S. character of some genera which are protean in Europe.

Describes how he distinguishes introduced and aboriginal stocks of the same species.

Describes problems of classifying species in highly variable genera. Lists highly variable genera. Comments on the list of Asa Gray. Says species may be made to appear more or less variable according to whether a genus is divided into few or many species.

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.

JDH thanks Asa Gray for his note of 10 Mar [1857]. Is impatient for LESSONS, apologises for not reviewing the MANUAL in the JOURNAL OF BOTANY. William Jackson Hooker wants JDH to review [Miles Joseph] Berkeley's INTRODUCTION TO CRYPTOGAMIC BOTANY, JDH praises its content but calls it 'appallingly written & arranged', a common failing of parson-authors such as Sedgwick & Buckland, Copewell[?] & Baden-Powell. An abstract of the Linnean Society's ideas on genera will appear in the LITERARY GAZETTE & a summary by Bentham in the Linnean journal. JDH is critical of the way Germans approach a subject, A. Braun's work on genera is an exemplar. JDH dismisses [Berthold Carl] Seemann's 'twaddle' about genera being objective or subjective, gives Rosa & Salix as examples of the former & Unbellifers as the 'confoundedly bad' latter. Discusses [Thomas] Thomson's paper on germination & embryos of Careya & Barringtonia. JDH worries about Gray doing a book on forest trees. Notes [Richard] Spruce is stranded in Tarapoto, in the Andes, en route to Lima. Mentions UK government expedition to the source of the Missouri & the East Rocky Mountains, [Eugène] Bourgeau is the botanist & the commander Mr Palliser. JDH's children & wife [Frances Hooker] are in Brighton. JDH suggests a visit to the UK would stimulate Gray's work on the Flora of North America. [Walter Hood] Fitch has produced plates of British natural orders, designed by [John Stevens] Henslow, for the National Schools under the Board of Trade. In a post script dated 30 Mar JDH gives a detailed opinion of Gray's ELEMENTS. JDH cannot visit Canada & USA until 1858, he has too much work, with the Indian Herbarium & Tasmanian flora for the Van Diemen's Land government, & not enough money. Comments briefly on Gray's notices in SILLIMAN & at length on De Candolle's botanical geography, referring to the work of de Heer, Henfrey, Brown, Forbe's Atlantis theory & Duchastre's encyclopaedia. Recommends that Gray get the GARDENERS' CHRONICLE.

Thanks for new part of "Statistics".

Interested in disjoined species; do they tend to belong to large or small genera, and are they generally members of small families?

Is glad AG will tackle introduced plants; has noticed that the proportion of a particular family to the whole flora tends to be similar in introduced and indigenous plants.

Discusses difficulties involved in deciding which genera are protean in the light of some comments by H. C. Watson.

Comments on species with disjoined ranges; does not feel, despite CD’s expectations, that they tend to belong to small families.

Gives the proportion of U. S. trees in which the sexes are separate [see Natural selection, p. 62].

Thanks for AG’s remarks on disjoined species. CD’s notions are based on belief that disjoined species have suffered much extinction, which is the common cause of small genera and disjoined ranges.

Discusses out-crossing in plants.

Has failed to meet with a detailed account of regular and normal impregnation in the bud. Podostemon, Subularia, and underwater Leguminosae are the strongest cases against him.

Believes, with CD, that extinction may be an important factor in explaining plant distributions, but sees no reason why the several species of a genus must ever have had a common or continuous area. "Convince me of that, or show me any good grounds for it … and I think you would carry me a good way with you". It is just such people as AG that CD has to satisfy and convince.

Feels that the crossing of individuals is important in repressing variation and perhaps in perpetuating the species, but instances some plants in which it cannot, apparently, take place.

Believes species have arisen, like domestic varieties, with much extinction, and that there are no such things as independently created species. Explains why he believes species of the same genus generally have a common or continuous area; they are actual lineal descendants.

Discusses fertilisation in the bud and the insect pollination of papilionaceous flowers. His theory explains why, despite the risk of injury, cross-fertilisation is usual in the animal and vegetable kingdoms, even in hermaphrodites.

States he has "misgivings about the definiteness of species". Believes there is some inherent tendency for plants to originate varieties. Cross-fertilisation is likely in most cases but sees difficulties with plants like Adlumia.

Encloses an abstract of his ideas on natural selection and the principle of divergence; the "means by which nature makes her species".

Discusses varieties and close species in large and small genera, finding some data from AG in conflict with his expectations.

Has been observing the action of bees in fertilising kidney beans and Lobelia.

No summary available.

Thanks AG for his criticisms of CD’s views; finds it difficult to avoid using the term "natural selection" as an agent.

Discusses crossing in Fumaria and barnacles.

Has received a naturally crossed kidney bean in which the seed-coat has been affected by the pollen of the fertilising plant.

Finds the rule of large genera having most varieties holds good and regards it as most important for his "principle of divergence".

JDH characterises himself to Asa Gray as a full throated critic. He often disagrees with his Father [William Jackson Hooker], who can be stuck in old ways of thinking, JDH stops him from publishing outdated views. They clashed over the JOURNAL [OF BOTANY] work, JDH is glad it is discontinued. JDH offers Gray species of Rubiaceae, he might bring them himself if he goes to the USA this year. Has consulted Huxley re. Gray's notes on vitality & offers his comments. Discusses his thoughts on dedoublement, at length, he has discussed the theory with [George] Bentham[GB] & does not consider it logical. Mentions Gray's work on Balanophoreae. Discusses in detail Dicotyledonous exogens & the hierarchy of flowering plants, enumerating the characteristics which should define the highest type. He thinks that the 'vegetable ladder' should be arranged by physiology of the reproductive organs with organic complexity secondary: this would elevate gymnosperms above Phaenogams. [Arthur] Henfrey has found the corpuscula[?] in Gnetum, he suspects the seeds take 7 years to ripen. JDH describes the development of Gnetum ovule during fertilisation. JDH is working on East India Company Assistant Surgeon competitive examination papers & Royal Society Report for [David] Livingstone's expedition. Comments that Gray has correctly described Sambucus fruit. Describes his observations on ovules in different plant genera & families: Viburnum, Caprifol[iaceae]. Conv[olvulaceae]. Aral[iaceae]. Umbelli[ferae]. Rubiaceae, with particular reference to raphe in Lonicerae. He suspects ovule structure will lead to affinities. He discusses his study of Chimonanthus, which he places nearer Monimiaceae & Annonads than Rosaceae, calycifloral characteristics being key. JDH thinks Cumming's Morinda is new. He is sending a fruit of Ceylon [Sri Lanka] Eupyrena. GB recommends his notes on Rubiaceae. Gray could send his notes on Timonius to the Linnean journal, JDH has not received the proof of Gray's Magnolia paper.

Asks whether botanists tend to record varieties more carefully in large genera or small genera.

Wants information on the ranges of varieties of a species compared to the range of the species.

No summary available.

List of close species taken from AG’s Manual of botany [1848].

Discusses the variation of species in large and small genera.

Thanks AG for his list of close species.

Laments the slow progress he makes with his book [Natural selection].

No summary available.