Thanks AG for 2d part of "Statistics [of the flora of the northern U. S.", Am. J. Sci. 2d ser. 22 (1856): 204–32; 2d ser. 23 (1857): 62–84, 369–403].

Is glad AG concludes species of large genera are wide-ranging, but is "riled" that he thinks the line of connection of alpine plants is through Greenland. Mentions comparisons of ranges worth investigating.

Believes trees show a tendency toward separation of the sexes and wonders if U. S. species bear this out. Asks which genera are protean in U. S.

JDH thanks Asa Gray for his letter & review of [Rev. Miles Joseph] Berkeley. Berkeley will not like Gray's review or JDH's in JOURNAL OF BOTANY. JDH comments on Gray's criticism of his ideas on physiology, comparing them to a firework, and to his own less ordered style of critique. Declares that he will not take account of a 'vital force' until anyone else does. Compares American & British terminology i.e. in the United States physiology is synonymous with biology. Discusses nomenclature & the use of the English 'anth' in names such as Ranunculanths, compared to using the suffixes: 'ads' or 'worts' in place of aceae. This was started by [John Stevens] Henslow & despite misgivings JDH has advised [George] Bentham to retain them as they are now effectively sanctioned by the government; being used in the National Schools. He asks Gray not to deter Bentham from using the system as it is the current vogue & it is hard enough to get government to publish such books for the amateur, & this class of people cares a great deal about terminology. JDH thinks [John] Lindley is correct to refer Podostemons to near Lentibulariaceae though he previously thought their place was with Scrophulariaceae.

No summary available.

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.

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 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.

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".