My dear Sir!

I am very much pleased that you have thought it worth while to controll my little communication, and to examine yourself some roots of plants to see their folds.¹ The root you sent me shows the phenomenon very clearly. I have not yet experienced on the influence of dryness or humidity, but I have found that cut roots contract also (in 24 hours) if lying wholly in water. However I observed with Carum Carvi² that roots of plants, growing in fissures of the earth showed more folds than those of plants of the same field, that had grown in compact earth. Should it not be possible, that specimens growing in loose earth or in fissures contract more because they are not hindered in doing so, whilst plants in compact soil have to surmount a great resistance, and become therefore less shorter, than they would do otherwise?

I am much obliged for your notice on Triticum roots, I have not yet paid attention to them and am therefore not able to answer your questions, but will examine it directly after my returning to Amsterdam.³

I am also much obliged for the kindness you had in writing for me to Prof. Asa Gray, and beg you to accept my sincere thanks for the benevolence you showed me in receiving me so very kindly at Abinger Hall.⁴

I remain | My dear Sir | Yours very truly | Hugo de Vries