From T. H. Farrer 9 May 1869
3 Gloucester Terrace | R.P.
9 May /69
My dear Mr Darwin.
Many thanks for your lesson—1 I think I see what you mean—that each plant lives as it best can, and survives because it has organs which suit it best; and consequently it is wrong to call any plant which lives & thrives “degrade〈d”—〉 Still when one finds an organ in one species fully developed & in full function: and the same organ with a similar structure in another species half developed & functionless, may one not (passing over the question whether the less perfect form is derived from the more perfect—or vice versâ, or both from some other form) say that the less perfect “organ” is “degraded?
I think that the poor Cephalanthera comes in for the term more than once in the book which is my great delight2
Very truly yours | T H Farrer
Thanks CD for lesson that it is wrong to call any plant which lives and thrives "degraded".