From J. D. Hooker [c. 4 March 1847]1
Natural groups having defined limits (sometimes wonderfully so) favourable to local causes effecting change in species.— Casual Appearance of one species of a limited (geographically) nat. group, in a remote quarter, (far from principal parallel—) & to which migration cannot stretch not necessarily subversive of theory—for these outlying species, though presenting the typ. charact. of such groups, often want the subtypical—& hence may not have immediately sprung from the great parent of that group— thus, the Eparid. (typical of N.H.)2 are seperated from Ericeæ Botanically by 1. locular anther & almost universally epipetalous stamina, but the Prionotes of Cape Horn—(its only S. Am. Repr.) has perigynous stam may such not the Prionotes be one Ericeæ of S. Am. becoming Eparid., cotemporaneously (at least independently) of the many Eric. of N.H. becoming so too: All the Pernettyas (Ericeæ) of S. Am have horned anthers—but the sole Pernettya of N.H has blunt (not horned) muticous anthers—may this be a link between Epacrid (all blunt) & Ericeæ; formed in N.H. independently of the Pernettyas formed out of Ericeæ in S. Am.
All allusions to superintending providence unnecessary— The Creator able to make first able also to go on directing & matter of moonshine to argument whether he does or no— All notice of interposition being unnecessary, is alarming to one class of readers, & uncalled for—rather expressly mention the design displayed in retaining useless organs for further modifications as proof of supervisal—
The greatest & most diffused Nat: group consequently the oldest & has survived greatest Geol. changes now Kerg. Cabbage most simple in structure of all Crucif— hence possibly crucif reached Kerg land when a large Continent helped—3
Notes on part of CD’s species sketch.
Please cite as
Darwin Correspondence Project, “Letter no. 1066,” accessed on 30 September 2016, http://www.darwinproject.ac.uk/DCP-LETT-1066