To J. D. Hooker   23 November 1880

My dear Hooker

Your note has pleased me much; for I did not expect that you would have had time to read any of it.—¹ Read the last chapt. & you will know whole result, but without the evidence. The case, however, of radicles bending after exposure for an hour to geotropism, with their tips (or brains) cut off is, I think worth your reading (bottom of p. 525); it astounded me. The next most remarkable fact, as it appears to me (p. 148) is the discrimination by the tip of the radicle between a slightly harder & softer objects affixed on opposite sides of tip. But I will bother you no more about my book.— The sensitiveness of seedlings to light is marvellous.—²

I have read Wallace with the greatest interest & admire it extremely; but I cannot swallow or digest all his conclusion;³ perhaps my brain-digestion is weak from old age. I can hardly credit that the opening of one or two N. & S. sea-channels across Europe & Asia w^d. warm Arctic regions enough for them to support such organisms as they formerly supported. It stumps me to believe that northern plants travelled down Andes to Fuegia,—thence to the supposed Antarctic continent, &c thence by insular halting places to S. Australia & (I think to) C. of Good Hope. That they sh^d. have been subjected to such a series of changes & retained the same specific character is to me almost incredible.⁴ But what I most object to is that seeds have been blown from one mountain-summit to another distant one. Wallace argues from dispersal to oceanic islands; but in this case we have sea-currents, & birds with dirt on feet & base of beak & seeds in stomach.⁵ No bird w^d fly directly from the tops of the Alps to the tops of the Pyrenees, & fancy seeds being often thus blown & not merely to the tops, but to where a debacle had recently occurred. I still remain convinced that when same species inhabits distant mountain-summits, they must formerly have inhabited intermediate low-lands,—⁶ Though Wallace argues very well against several former glacial periods & almost convinced me, I feel inclined to admit them, as the sole means of explaining the temperate forms at the C. of Good Hope. How I wish you had time to take up this great subject again. It pleased me to see how well Wallace appreciates your work.—⁷

I feel inclined to abide by view where oceans now extend, they have always (ie since Silurian times) nearly extended, & so with continents; but it is an awfully perplexing subject.—

I was delighted with Pagets Essay;⁸ I hear that he has occasionally attended to this subject from his youth. I thought he made too much of the symmetry of decay in leaves.— I am very glad he has called attention to galls— this has always seemed to me a profoundly interesting subject; & if I had been younger would take it up.—⁹ By Jove his essay will have borne good fruit if it gives you a pathologist.—¹⁰

Frank shall answer about Nobbe, when he comes home.—¹¹

What word could I use for zig-zag which you hate so much?¹²

With hearty thanks | farewell my dear Hooker. | Yours ever | Ch. Darwin

Reading this over again I do not think I have expressed strong enough admiration of Wallace’s book.— His weakness is want of sound judgment, as it appears to me,— videlicet Spiruatilism.—¹³