My dear Hooker

If my memory serves me rightly Dyer has left Kew for his holidays, & so I write to you to ask you if by any chance you have seeds of Lathyrus aphaca or any young seedlings 2 or 3 of which could be potted.² If I receive no answer I shall understand that you cannot aid me.— I want to try whether the tendrils are apheliotropic, for I record that they revolve very little, I conjecture that they may find a support by bending towards any dark object.—³

Our book on the movements of Plants will, I think, contain a good deal of new matter, but will be intolerably dull.⁴ I have been working pretty hard of late & want rest & change, so we all go on August 1^st to Coniston for a month.⁵ It is an awful journey to me.— It is a long time since I have heard any news of you & yours, & what you are doing & intending to do. Frank comes back in the beginning of next month from Würzburg, where he has been working pretty hard on various subjects & practising dissection, cutting slices &c.—⁶

I have just read Balls’ essay. It is pretty bold. The rapid development, as far as we can judge, of all the higher plants within recent geological times is an abominable mystery. Certainly it w^d be a great step if we could believe that the higher plants at first could live only at a high level; but until it is experimentally that Cycadeæ, Ferns &c can withstand much more carbonic acid than the higher plants, the hypothesis seems to me far too rash.⁷ Saporta believes that there was an astonishingly rapid development of the higher plants, as soon flower-frequenting insects were developed & favoured intercrossing.⁸ I sh^d. like to see this whole problem solved.

I have fancied that perhaps there was during long ages a small isolated continent in the S. hemisphere, which served as the birth place of the higher plants; but this is a wretchedly poor conjecture. It is odd that Ball does not allude to the obvious fact that there must have been alpine plants before the Glacial period, many of which w^d have returned to the mountains after the glacial period when the climate again became warm. I always accounted to myself in this manner for the Gentians &c.—

Ball ought also to have considered the Alpine insects common to the Arctic regions. I do not know how it may be with you, but my faith in the Glacial migration is not at all shaken.⁹

Ever my dear old friend yours truly | Ch. Darwin

P.S. I shall have to return some plants to Kew when we leave home.— Your plant of Smilax aspera has been injured by scale insects which were only lately detected.—¹⁰ Is this worth returning? It is a large bush.