My dear Hooker

Thanks for the interesting letter; I can however hardly believe that each Var. of the grasshopper has always been bred in its own district. What a pity she did not enclose under glass, living specimens on differently coloured surfaces.²

I am very glad to hear that you are going on with y^r flora.³ W^d it be worth while my looking through my M.S index of Gardener’s Chron. for any little facts for you.⁴

Now I want to beg for assistance for the new Ed. of Origin.⁵ Nägeli justly urges that plants offer many morphological differences, which from being of no service cannot have been selected, & which he accounts for by an innate principle of progressive development. I find old notes about this difficulty, but I have hitherto slurred it over.⁶ Nägeli gives as instances the alternate & spiral arrangement of leaves, & the arrangement of the cells in the tissues.⁷ W^d you not consider as a morpholog. difference the trimerous tetramerous &c divisions of flowers,—the ovules being erect or suspended, their attachment being parietal or placental,—& even the shape of the seed when of no service to the plant.

Now I have thought, & want to show, that such differences follow in some unexplained manner from the growth or development of plants which have passed thro’ a long series of adaptive changes. Any how I want to shew that these differences do not support the idea of progressive development.⁸ Cassini states that the ovaria on the circumference & centre of Compos. flowers differ in essential characters, & so do the seeds in sculpture.⁹ The seeds of umbelliferæ in the same relative positions are coelospermous & orthospermous.¹⁰ There is a case given by Aug. S^t Hilaire of an erect & suspended ovule in the same ovarium, but perhaps this hardly bears on the point.¹¹ The summit flower in Adoxa & rue differ from the lower flowers;¹² What is difference in flowers of the Rue? how is the ovarium? especially in the rue? as Aug. S^t Hilaire insists on the locularity of the ovarium varying on the same plant in some of the rutaceæ.—¹³ Such differences do not speak, as it seems to me, in favour of progressive Development.—Will you turn subject in your mind, & tell me any sure facts.— Differences in structure in flowers in different parts of same plant, seem best to show that they are result of growth or position or amt of nutriment.—

I have got your Photograph over my chimney-piece & like it much;¹⁴ but you look down so sharp on me that I shall never be bold enough to wriggle myself out of any contradiction—

Yours affect. | C. Darwin

Owen pitches into me & Lyell in grand style in last chapt of vol. 3 of Anat. of Vertebrates.—¹⁵ He is a cool hand— he puts words from me in inverted commas & alters them.—