Dear Darwin

Your DC. results are very curious & suggestive.² I see no objection to your lumping all the orders (Polygon. Labiatæ, Scrophul. Borrag. together, but not Proteaceæ, or if you do include Proteaceæ it should be also alluded to seperately in a foot note as well, because its distribution is so very local.³

Now with regard to Labiatæ there is a great deal to be said, though perhaps not much that will be satisfactory to you. In the first place it is not only as Natural an Order as any in the Vegetable Kingdom, but one of the largest & best limited & the most equably diffused. & is the best elucidated of any of its size both generically & specifically of any:—about this there are not two opinions amongst Botanists. It therefore forms a formidable obstacle to you & must be studied a little carefully.⁴

I would strongly wish to see you take more vols of DC., especially Compositæ, Ericeæ & others, for I cannot think that your case will be established upon any but such evidence as is afforded by plants spread over the whole globe— That in small areas, the species of large genera are more variable than of small, may not argue that the same holds good for same genera in large areas⁵

Such facts as Rubus being variable in Europe & not so in Himalaya prove this— It is also to be remembered that a form marked enough to be ranked as a variety in a local Flora, may not have that value—in a general Flora.

Benthams late researches into the British Flora, have so greatly modified his views of the limits of species, that in my eyes they invalidate the results of local Floras very materially. He has now completed the MSS of his British Flora,⁶ having studied every species from all parts of the world, & most of them alive in Britain, France & other parts of Europe— Well—he has turned out as great a lumper as I am! & worse.⁷ Then did you see a paper of Decaisne’s on Pyrus, translated in Gard. Chron about 3 weeks ago⁸ —in which he adopts Thomsons & my views of species & says that if he had to monograph. Plantago again he would reduce whole sections to one species:—& of course as many species (i.e. marked forms would then rank as varieties.— Now it was Decaisne (a most admirable Botanist) who on receiving the Fl. Indica wrote me most kindly & earnestly begging me to reconsider my mode of viewing species, & hinting that I was going to the devil.— All this does not directly affect your results, but it shows that you should draw them from materials of all kinds—local & general, & from systematists of all shades of opinion. A comparison of Babingtons & Benthams Floras⁹ will be invaluable: the latter will be out at Easter

I find that Linum Catharcticum has occasionally the upper leaves alternate—:¹⁰ normally all are opposite except the upper floriferous, which latter are normally always alternate— I find that in one or two cases an alternate non-floriferous upper pair, which may be theoretically accounted for by the [illeg] of the flower-buds. ¹¹

I send the Cucubalus &c list,¹² & will forward the remaining answers soon

Write to D^r. Ferdinand Mueller Govt. Botanist Melbourne Victoria Australia & use your own name—& ours too if you like— he will be tremendously proud to hear from you—is a good active Botanist & will do your behests—¹³ He is coming home in 1859 so put him up to all you want done toute suite — Also try Chas: Moore Esq Govt. Botanic Garden Sydney—a second-rate man, but quite capable of giving you good information—¹⁴ I know of nobody at Cape of Good Hope.

I think the fact of moisture favouring extension of species is a very important one for you