Sends a reference to Subularia which bears on a query CD made some time ago [see 2002]. Subularia was seen to flower in the air in a remarkably dry season.
Sends a reference to Subularia which bears on a query CD made some time ago [see 2002]. Subularia was seen to flower in the air in a remarkably dry season.
Will shortly return CD’s list of varieties of British plants. Discusses the situations in which different varieties of species are often found and the ranges of varieties relative to those of the species.
Finds he cannot annotate CD’s list of subspecies and varieties as wanted. Mentions again his difficulties with "species"; he "cannot find the proof of species being definite and immutable whatever they may seem to be at any one time and spot".
Discusses the ranges and distribution of varieties relative to the type species.
Believes that botanists tend to mark more varieties in large than in small genera, but notes that where many varieties of a species exist these varieties may well be passed over, whereas similar varieties of another species which are fewer in number may well be recorded.
Discusses the ranges of species in large and small genera; difficulties involved in limiting the discussion to Britain.
Believes natural selection will become recognised as an established truth in science, though it will shock the ideas of many men.
Sends a correction for Origin reprint.
Notes by HCW on the Origin dealing especially with divergence and convergence. Believes there is some natural tendency to converge into groups in opposition to divergence generated by natural selection.
Returns reviews of Origin.
F. J. Pictet [Arch. Sci. Phys. & Nat. n.s. 7 (1860): 231–55] goes further than he himself realises.
Naturalists will resist CD’s views until faith in certain "impassable" barriers between existent species is shaken.
Gives CD an instance of convergence.
Distribution of varieties and subspecies.
George Maw’s review of the Origin [Zoologist 19 (1861): 7577–611].
The Primula experiments of J. Sidebotham; HCW’s distrust of the results [see J. Sidebotham, "Specific identity of the cowslip and the primrose", Phytologist 3 (1849): 703–5].
Taeas [?] allied to L. hyssopifolia. [Cover containing packets of seed specimens.] Mentioned in the letter to H. C. Watson, 28 May [1864], f.2 (fS 4512).
Difficulty of distinguishing varieties and species. Did HCW suggest a printed list that might help?
Polymorphic genera.
On geographical distribution of plants. Plant systematics and natural classification.
Do the plants that are common to Europe and North America nearly all live north of the Arctic Circle? CD bases his question on HCW’s "capital" comparison between relations of Europe to North America and Europe to E. Asia if the intervening land had been submerged. CD has been led to speculate that in the mid-Pliocene the organisms now living in middle Europe and northern U. S. lived within the Arctic Circle. Subsequent movements of this flora with advance and retreat of glaciers would explain present distribution better than Forbes’s vast submergences.
Discusses the possibility of "convergence" occurring; believes it could be only very limited.
Asks HCW’s help with his experiments on Lythrum salicaria, for which he needs flowers of the rare Lythrum hyssopifolia.
Thanks HCW for Lythrum specimens.
CD has at last finished his Lythrum paper. ["Three forms of Lythrum", Collected papers 2: 106–31.]