chance. But I have NONE in the vegetable kingdom, owing, as I believe, to my ignorance. If Nepenthes consisted of ONE or two species in a group with a pitcher developed, then I should have expected it to have been very variable; but I do not consider Nepenthes a case in point, for when a whole genus or group has an organ, however anomalous, I do not expect it to be variable,—it is only when one or few species differ greatly in some one part or organ from the forms CLOSELY ALLIED to it in all other respects, that I believe such part or organ to be highly variable. Will you turn this in your mind? It is an important apparent LAW (!) for me.
Ever yours, C. DARWIN.
P.S.—I do not know how far you will care to hear, but I find Moquin-Tandon treats in his 'Teratologie' on villosity of plants, and seems to attribute more to dryness than altitude; but seems to think that it must be admitted that mountain plants are villose, and that this villosity is only in part explained by De Candolle's remark that the dwarfed condition of mountain plants would condense the hairs, and so give them the APPEARANCE of being more hairy. He quotes Senebier, 'Physiologie Vegetale,' as authority—I suppose the first authority, for mountain plants being hairy.
If I could show positively that the endemic species were more hairy in dry districts, then the case of the varieties becoming more hairy in dry ground would be a fact for me.
CHARLES DARWIN TO J.D. HOOKER. Down, June 3rd [1857].
My dear Hooker,
I am going to enjoy myself by having a prose on my own subjects to you, and this is a greater enjoyment to me than you will readily understand, as I for months together do not open my mouth on Natural History. Your